Polyurethanes and graft copolymers based on polyurethane, and their use for producing coating materials, adhesives, and sealing compounds

ABSTRACT

A hydrophilic or hydrophobic polyurethane having at least one olefinically unsaturated group selected from the group consisting of pendant olefinically unsaturated groups, terminal olefinically unsaturated groups, and mixtures thereo wherein the pendant olefinically unsaturated groups are sele consisting of pendant olefinically unsaturated groups which are attached to a cycloaliphatic group which represents a link in the polymer main chain and pendant olefinically unsaturated groups which are present as a double bond in a cycloolefinic group which constitutes a link in the polymer main chain, and the terminal olefinically unsaturated groups are selected from the group consisting of terminal olefinically unsaturated groups which are attached to a cycloaliphatic group which forms an endgroup of the polymer main chain and terminal olefinically unsaturated groups which are present as a double bond in a cycloolefinic structure which forms en endgroup of the polymer main chain.

The present invention relates to novel polyurethanes and to novelpolyurethane-based graft copolymers. The present invention furtherrelates to novel processes for preparing polyurethanes andpolyurethane-based graft copolymers. The present invention furtherrelates to the use of the novel polyurethanes and of the novelpolyurethane-based graft copolymers to prepare coating materials,adhesives, and sealing compounds. Furthermore, the present inventionrelates to novel coating materials, adhesives, and sealing compounds,especially aqueous coating materials, adhesives, and sealing compounds.The present invention relates not least to novel coats, adhesive films,and seals obtainable from the novel, especially aqueous, coatingmaterials, adhesives, and sealing compounds. In particular the presentinvention relates to single-coat or multicoat decorative and/orprotective coating systems, especially multicoat color and/or effectcoating systems.

Polyurethane-based graft copolymers are known. They are normallyprepared by the graft copolymerization of olefinically unsaturatedmonomers in the aqueous dispersion of a hydrophilic or hydrophobicpolyurethane whose polymer chain includes terminal and/or lateral,olefinically unsaturated groups. Groups of this kind may be incorporated

-   -   into the polyurethane chain by way of maleic acid or fumaric        acid and/or their esters,    -   laterally to the polyurethane chain by way of compounds having        two isocyanate-reactive groups and at least one olefinically        unsaturated group or by way of compounds having two isocyanate        groups and at least one olefinically unsaturated group,        terminally to the polyurethane chain by way of compounds having        one isocyanate-reactive group and at least one olefinically        unsaturated group or by way of compounds having one isocyanate        group and at least one olefinically unsaturated group, or    -   by way of anhydrides of alpha,beta-unsaturated carboxylic acids.

By way of example, reference is made to patent applications and patentsDE 197 22 862 C2, DE 196 45 761 A1, EP 0 401 565 A1, EP 0 522 420 A1, EP0 522 419 A2, EP 0 755 946 A1, EP 0 608 021 A1, EP 0 708 788 A1 or EP 0730 613 A1, and also German Patent Applications DE 199 53 446.2 or DE199 53 203.6, unpublished at the priority date of the presentspecification.

Moreover, German Patent Applications DE 199 48 004.4-44, unpublished atthe priority date of the present specification, describes externallycrosslinking polyurethanes containing pendant, i.e., lateral,ethenylarylene groups as grafting sites, and the correspondingexternally crosslinking graft copolymers.

Furthermore, German Patent Application DE 199 53 445.4-44, unpublishedat the priority date of the present specification, describes thecorresponding self-crosslinking polyurethanes and theirself-crosslinking graft copolymers.

In the context of the present invention, the property of hydrophilicitydenotes the constitutional property of a molecule or functional group topenetrate into the aqueous phase or to remain therein. Accordingly, inthe context of the present invention, the property of hydrophobicitydenotes the constitutional property of a molecule or functional group tobehave exophilically with respect to water, i.e., to tend not topenetrate into water or to tend to depart the aqueous phase. For furtherdetails, reference is made to Römpp Lexikon Lacke und Druckfarben, GeorgThieme Verlag, Stuttgart, N.Y., 1998, “Hydrophilicity”,“Hydrophobicity”, pages 294 and 295.

In the context of the present invention, the term “self-crosslinking”denotes the capacity of a binder to enter into crosslinking reactions ofitself. A prerequisite for this is the presence in the polyurethanes andthe graft copolymers of complementary reactive functional groups whichreact with one another and so lead to crosslinking. Alternatively, thepolyurethanes and graft copolymers contain reactive functional groupswhich react “with themselves”. The term externally crosslinking, on theother hand, is used to refer to those polyurethanes and graft copolymersin which one variety of the complementary reactive functional groups ispresent in the polyurethanes and graft copolymers and the other varietyis present in a hardener, curing agent or crosslinking agent. Forfurther details, reference is made to Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, N.Y., 1998, “Curing”, pages274 to 276, especially page 275, bottom.

The known polyurethane-based graft copolymers are used especially forthe preparation of waterborne coating materials. The known waterbornecoating materials serve primarily to produce color and/or effectbasecoats in multicoat coating systems by the wet-on-wet technique, asare described, for example, in the patents and patent applicationsrecited above.

Nevertheless, the preparation of the known polyurethane-based graftcopolymers may cause problems.

For instance, lateral and/or terminal allyl groups are oftenincorporated as grafting centers. However, the reactivity of the allylgroups is comparatively low. If the more reactive acrylate ormethacrylate groups are used instead, gelling of the polyurethanes mayoccur before or during the graft copolymerization.

In some cases it is possible, not least, for the amount of olefinicallyunsaturated groups in the polyurethanes to prove too low for completegrafting, with the consequence that a large proportion of the monomersintended for grafting on forms separate homopolymers and/or copolymersalongside the polyurethane, which may adversely affect the performanceproperties of the graft copolymers and of the coating materials,adhesives, and sealing compounds prepared with them. This disadvantagecannot be easily eliminated by raising the double-bond fraction in thepolyurethanes to be grafted, since to do so is detrimental to otherimportant performance properties of the polyurethanes.

For instance, in the case of overcoating with powder slurry clearcoats,the clearcoat may crack during baking and/or may undergo delamination,especially after the water jet test. Moreover, popping marks may appear.

It is an object of the present invention to provide new hydrophilic andhydrophobic olefinically unsaturated polyurethanes which have not onlyterminal but also pendant olefinically unsaturated groups, which may beprepared simply and purposively without the risk of product damage, andwhich constitute excellent grafting bases for olefinically unsaturatedmonomers.

A further object of the present invention is to find a new process forpreparing olefinically unsaturated polyurethanes which simply,purposively and without the risk of product damage provides hydrophilicor hydrophobic polyurethanes having pendant and/or terminal olefinicallyunsaturated groups.

Another object of the present invention is to find new graft copolymersin the form of primary dispersions or secondary dispersions which may beprepared simply, purposively and without the risk of product damage.

The novel graft copolymers should be physically curing, thermallyself-crosslinking or externally crosslinking, or curable thermally andwith actinic radiation (dual cure).

In the context of the present invention, the term “physical curing”means the curing of a polyurethane or of a graft copolymer by filming,linking taking place within a coating by way of formation of loops ofthe polymer molecules of the binders (regarding the term cf. RömppLexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, N.Y.,1998, “Binders”, pages 73 and 74). Alternatively, filming takes place bythe coalescence of polymer particles (cf. Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, N.Y., 1998, “Curing”, pages274 and 275). Normally, no crosslinking agents are required for thispurpose. If desired, physical curing may be assisted by atmosphericoxygen, heat, or exposure to actinic radiation.

In the context of the present invention, actinic radiation iselectromagnetic radiation, such as visible light, UV radiation orX-radiation, especially UV radiation, and corpuscular radiation such aselectron beams.

Yet another object of the present invention is to provide new aqueousand nonaqueous, physically curing, thermally self-crosslinking orexternally crosslinking, or heat- and actinic-curing, polyurethane-basedcoating materials, adhesives and sealing compounds having very goodperformance properties. In particular the intention is to provide newcoating materials, especially new aqueous coating materials,specifically new aqueous basecoats, from which the disadvantages of theprior art are now absent and which instead are outstandingly suitablefor application by the wet-on-wet technique. In this context, even withthe use of powder clearcoat slurries, there should be no cracking(mudcracking) in the clearcoats, delamination of the clearcoats afterthe water jet test, or popping marks or pinholes. The new coatingmaterials should possess very good storage stability, outstandingapplication properties, such as very good leveling and very littletendency to run, even at high coat thicknesses, an outstanding overallvisual appearance, and high chemical resistance and weatheringstability. Moreover, the new coating materials, adhesives and sealingcompounds should have these advantageous properties both asone-component systems and as two-component or multicomponent systems.

In the context of the present invention, two-component or multicomponentsystems are coating materials, adhesives and sealing compounds whosecrosslinking agent, owing to its high reactivity, has to be storedseparately from other constituents of the coating materials, adhesivesand sealing compounds prior to application.

Accordingly, we have found the novel hydrophilic or hydrophobicpolyurethane having at least one pendant and/or at least one terminalolefinically unsaturated group, in which

-   1. the pendant olefinically unsaturated group    -   1.1 is attached to a cycloaliphatic group which represents a        link in the polymer main chain, or    -   1.2 is present as a double bond in a cycloolefinic structure        which represents a link in the polymer main chain, and-   2. the terminal olefinically unsaturated group    -   2.1 is attached to a cycloaliphatic group which forms an end        group of the polymer main chain, or    -   2.2 is present as a double bond in a cycloolefinic structure        which forms an end group of the polymer main chain.

In the text below, the novel hydrophilic or hydrophobic polyurethanehaving at least one pendant and/or at least one terminal olefinicallyunsaturated group is referred to as the “polyurethane of the invention”.

We have further found the novel graft copolymer preparable by(co)polymerizing at least one olefinically unsaturated monomer in thepresence of the polyurethane of the invention.

In the text below, the novel graft copolymer based on the polyurethaneof the invention is referred to as the “graft copolymer of theinvention”.

We have additionally found the novel adhesives, sealing compounds andcoating materials, in particular coating materials, especially aqueouscoating materials, specifically aqueous basecoats, which comprise atleast one polyurethane of the invention and/or at least one graftcopolymer of the invention and which are referred to below as adhesives,sealing compounds and coating materials of the invention.

Further subjects of the invention will emerge from the description.

In the light of the prior art it was surprising, and unforeseeable forthe skilled worker, that the complex problem on which the presentinvention was based, could be solved with the aid of the polyurethanesof the invention and/or of the graft copolymers of the invention. Aparticular surprise was that the polyurethanes of the invention and thegraft copolymers of the invention can be prepared simply and purposivelywithout damage to the products of the invention. A further surprise wasthe extremely broad usefulness of the polyurethanes of the invention andof the graft copolymers of the invention. It was totally unforeseeablethat the graft copolymers of the invention, in particular, give aqueousbasecoats which may be processed together with powder clearcoat slurriesby the wet-on-wet technique to form outstanding multicoat color and/oreffect coating systems without any cracking (mudcracking) in theclearcoats, delamination of the clearcoats after the water jet test, orpopping marks or pinholes.

The polyurethane of the invention comprises at least one pendant and/orat least one terminal olefinically unsaturated group. Alternativelyexpressed, the polyurethane of the invention comprises at least onependant, at least one terminal, or at least one pendant and at least oneterminal olefinically unsaturated group. In this context, thepolyurethanes of the invention which comprise at least one pendantolefinically unsaturated group afford particular advantages and aretherefore particularly preferred in accordance with the invention.

The polyurethane of the invention is hydrophobic or hydrophilic in theabovementioned sense. In terms of their use to prepare the graftcopolymers of the invention, the hydrophilic polyurethanes of theinvention afford advantages and are therefore used with preference.

The pendant olefinically unsaturated group either is attached to acycloaliphatic group which represents a link in the polymer main chainor is present as a double bond in a cycloolefinic group which likewiserepresents a link in the polymer main chain.

The terminal olefinically unsaturated group is attached to acycloaliphatic group which forms an end group of the polymer main chain,or it is present as a double bond in a cycloolefinic group whichlikewise forms an end group of the polymer main chain.

In accordance with the invention, two or more olefinically unsaturatedgroups may be attached to one cycloaliphatic group. It is of advantage,however, if only one olefinically unsaturated group is attached to onecycloaliphatic group.

Suitable olefinically unsaturated groups are, fundamentally, all groupscontaining at least one, especially one, double bond. In the context ofthe present invention, a double bond is a carbon-carbon double bond.Examples of highly suitable olefinically unsaturated groups are(meth)acrylate, ethacrylate, crotonate, cinnamate, vinyl ether, vinylester, vinyl, dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl,allyl and/or butenyl groups; dicyclopentadienyl ether, norbornenylether, isoprenyl ether, isopropenyl ether, allyl ether or butenyl ethergroups; and/or dicyclopentadienyl ester, norbornenyl ester, isoprenylester, isopropenyl ester, allyl ester and/or butenyl ester groups. Ofthese, the vinyl groups are particularly advantageous and are thereforeused with particular preference.

Similarly, two or more double bonds may be present in one cycloolefinicgroup. It is of advantage if there is only one double bond percycloolefinic group.

In a polyurethane of the invention, both the above-describedcycloaliphatic groups and the above-described cycloolefinic groups maybe present.

In accordance with the invention, the cycloaliphatic groups are ofadvantage and are therefore used with preference.

The cycloaliphatic groups may be derived from any desiredcycloaliphatics. In accordance with the invention it is of advantage ifthey are derived from cycloaliphatics having 4 to 12 carbon atoms in themolecule.

The cycloolefinic groups, similarly, may be derived from any desiredcycloolefins. In accordance with the invention it is of advantage ifthey are derived from cycloolefins having 4 to 12 carbon atoms in themolecule.

Examples of highly suitable cycloaliphatics are cyclobutane,cyclopentane, cyclohexane, cycloheptane, cycloctane, norbornane,bicyclo[2.2.2]octane, decalin, hydroindane, dicylcopentene,tricyclodecane or adamantane, but especially cyclohexane.

Examples of highly suitable cycloolefins are cyclopentene, cyclohexene,cycloheptene, cyclooctene, norbornene, bicyclo[2.2.2]octene ordicylclopentene.

The polyurethane of the invention may be prepared by a very wide varietyof methods of polymer chemistry. It is of advantage, however, to preparethe polyurethane of the invention by reacting

-   (i) at least one polyurethane prepolymer having at least one free    isocyanate group in the molecule with-   (ii) at least one cycloaliphatic having at least one, especially    one, olefinically unsaturated group and having at least two,    especially two, isocyanate-reactive groups in the molecule, and/or    with-   (iii) at least one cycloolefin having at least one, especially one,    double bond and having at least two, especially two,    isocyanate-reactive groups in the molecule.

If an excess of isocyanate groups over the isocyanate-reactive groups isemployed in the reaction, the cycloaliphatics (ii) and/or thecycloolefins (iii) are incorporated predominantly or exclusively intothe polymer main chain. If, on the other hand, an excess ofisocyanate-reactive groups over the isocyanate groups is employed, thecycloaliphatics (ii) and/or the cycloolefins (iii) are convertedpredominantly or exclusively to end groups. The skilled worker,therefore, is able easily to control the reaction so as to obtainpolyurethanes of the invention having the desired structures.

The cycloaliphatics (ii) or the cycloolefins (iii) comprise at least twoisocyanate-reactive groups. In other words, they may contain two, three,four or more isocyanate-reactive groups in the molecule. It is alsopossible to use mixtures of cycloaliphatics (ii) and/or cycloolefins(iii) each having a different number of isocyanate-reactive groups inthe molecule. Thus it is possible, for example, to use mixtures ofcycloaliphatics (ii) and/or cycloolefins (iii) having two andcycloaliphatics (ii) and/or cycloolefins (iii) having threeisocyanate-reactive groups in the molecule. By this means it is possibleto prepare branched polyurethanes of the invention in a simple manner.It is advantageous in this context to use the compounds (ii) and/or(iii) of higher functionality in minor amounts in order to preventgelling of the reaction mixture. In the great majority of cases,however, only bifunctional cycloaliphatics (ii) and/or cycloolefins(iii) are used.

Examples of suitable isocyanate-reactive groups are and hydroxyl, thioland/or primary and/or secondary amino groups. In accordance with theinvention, hydroxyl groups are of advantage and are therefore used withpreference.

Examples of suitable olefinically unsaturated groups for thecycloaliphatics (ii) are those described above, of which the vinylgroups is used with particular preference.

Examples of highly suitable cycloaliphatics (ii) are the positionallyisomeric vinyl-substituted polyhydroxy derivatives, especially thedihydroxy derivatives, of cyclobutane, cyclopentane, cyclohexane,cycloheptane, cycloctane, norbornane, bicyclo[2.2.2]octane, decalin,hydroindane, dicylcopentane, tricylclodecane or adamantane.

Examples of highly suitable cycloolefins (iii) are the positionallyisomeric polyhydroxy derivatives, especially the dihydroxy derivatives,of cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornene,bicyclo[2.2.2]octene or dicylclopentene.

In accordance with the invention, the positionally isomericvinylcyclohexanadiols (ii) 1-vinylcyclohexane-2,6-, -3,6-, -4,6-, -2,3-,-3,4- and/or -3,5-diol are very particularly advantageous and aretherefore used with very particular preference. The positionallyisomeric vinylcyclohexanediols (ii) are customary and known compoundsand are obtained as mixtures in industrial syntheses. In the text below,they are referred to for the sake of brevity as “vinylcyclohexanediol”.

The polyurethane prepolymer (i) is of linear, branched or comb, butespecially linear, construction. In this context the linear polyurethaneprepolymer (i) includes preferably two free isocyanate groups,especially two terminal free isocyanate groups. The branched orcomb-constructed polyurethane prepolymers (i) include preferably atleast two, in particular more than two, free isocyanate groups, terminalfree isocyanate groups being preferred.

In terms of method, the preparation of the polyurethane prepolymers (i)for use in accordance with the invention has no special features butinstead takes place, for example, as described in patent DE 197 22 862C1 or in patent applications DE 196 45 761 A1, EP 0 522 419 A1 or EP 0522 420 A1, by reaction of a polyol, especially a diol, with at leastone polyisocyanate, especially a diisocyanate, the isocyanate componentbeing employed in a molar excess.

For the preparation of the polyurethane prepolymers (i) it is preferredto use diisocyanates and also, if desired, in minor amounts,polyisocyanates, for the purpose of introducing branches. In the contextof the present invention, minor amounts are amounts which do not causegelling of the polyurethane prepolymers (i) during their preparation.This may also be prevented by using small amounts of monoisocyanates.

Examples of suitable diisocyanates are isophorone diisocyanate (i.e.,5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane),5-isocyanato-1(2-isocyanatoeth-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-trimethylcyclohexane,1-isocyanato-2-(3-isocyanatoprop-1-yl)cyclohexane,1-isocyanato-2-(3-isocyanatoeth-1-yl)cyclohexane,1-isocyanato-2-(4-isocyanatobut-1-yl)cyclohexane,1,2-diisocyanatocyclobutane, 1,3-diisocyanatocyclobutane,1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane,1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane,1,4-diisocyanatocyclohexane, dicyclohexylmethane 2,4′-diisocyanate,trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylene diisocyanate, ethylethylene diisocyanate,trimethylhexane diisocyanate, heptanemethylene diisocyanate ordiisocyanates derived from dimeric fatty acids, as marketed under thecommercial designation DDI 1410 by the company Henkel and described inpatents WO 97/49745 and WO 97/49747, especially2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane, or 1,2-, 1,4-or 1,3-bis(isocyanatomethyl)cyclohexane, 1,2-, 1,4- or1,3-bis(2-isocyanatoeth-1-yl)cyclohexane,1,3-bis(3-isocyanatoprop-1-yl)cyclohexane, 1,2-, 1,4- or1,3-bis(4-isocyanatobut-1-yl)cyclohexane, liquidbis(4-isocyanatocyclohexyl)methane with a trans/trans content of up to30% by weight, preferably 25% by weight, and in particular 20% byweight, as is described [lacuna] patents DE 44 14 032 A1, GB 1 220 717A, DE 16 18 795 A1 or DE 17 93 785 A1; tolylene diisocyanate, xylylenediisocyanate, bisphenylene diisocyanate, naphthylene diisocyanate ordiphenylmethane diisocyanate.

Examples of suitable polyisocyanates are the isocyanurates of thediisocyanates described above.

Examples of highly suitable monoisocyanates are phenyl isocyanate,cyclohexyl isocyanate or stearyl isocyanate.

The polyurethane prepolymers (i) are also prepared using

-   -   saturated and unsaturated polyols of relatively high and low        molecular mass, especially diols and, in minor amounts, triols        for the purpose of introducing branches, and also, if desired,    -   compounds which introduce hydrophilic functional groups,    -   polyamines, and    -   amino alcohols.

Examples of suitable polyols are saturated or olefinically unsaturatedpolyester polyols which are prepared by reacting

-   -   unsulfonated or sulfonated saturated and/or unsaturated        polycarboxylic acids or their esterifiable derivatives, alone or        together with monocarboxylic acids, and    -   saturated and/or unsaturated polyols, alone or together with        monools.

Examples of suitable polycarboxylic acids are aromatic, aliphatic andcycloaliphatic polycarboxylic acids. Preference is given to the use ofaromatic and/or aliphatic polycarboxylic acids.

Examples of suitable aromatic polycarboxylic acids are phthalic acid,isophthalic acid, terephthalic acid, phthalic, isophthalic orterephthalic acid monosulfonate, or halophthalic acids, such astetrachlorophthalic or tetrabromophthalic acid, among which isophthalicacid is advantageous and is therefore used with preference.

Examples of suitable acyclic aliphatic or unsaturated polycarboxylicacids are oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,undecanedicarboxylic acid or dodecanedicarboxylic acid, or maleic acid,fumaric acid or itaconic acid, of which adipic acid, glutaric acid,azelaic acid, sebacic acid, dimeric fatty acids and maleic acid areadvantageous and are therefore used with preference.

Examples of suitable cycloaliphatic and cyclic unsaturatedpolycarboxylic acids are 1,2-cyclobutanedicarboxylic acid,1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid,1,3-cyclopentanedicarboxylic acid, hexahydrophthalic acid,1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,4-methylhexahydrophthalic acid, tricyclodecanedicarboxylic acid,tetrahydrophthalic acid or 4-methyltetrahydrophthalic acid. Thesedicarboxylic acids may be used both in their cis and in their trans formand also as a mixture of both forms.

Further examples of suitable polycarboxylic acids are polymeric fattyacids, especially those having a dimer content of more than 90% byweight, which are also known as dimeric fatty acids.

Also suitable are the esterifiable derivatives of the abovementionedpolycarboxylic acids, such as their monoesters or polyesters withaliphatic alcohols having 1 to 4 carbon atoms or hydroxy alcohols having1 to 4 carbon atoms, for example. It is also possible to use theanhydrides of the abovementioned polycarboxylic acids, where they exist.

Together with the polycarboxylic acids it is also possible if desired touse monocarboxylic acids, such as, for example, benzoic acid,tert-butylbenzoic acid, lauric acid isononanoic acid, fatty acids ofnaturally occurring oils, acrylic acid, methacrylic acid, ethacrylicacid or crotonic acid. The preferred monocarboxylic acid used isisononanoic acid.

Examples of suitable polyols are diols and triols, especially diols.Normally, triols are used alongside the diols in minor amounts in orderto introduce branches into the polyester polyols. In the context of thepresent invention, minor amounts are amounts which do not cause gellingof the polyester polyols during their preparation.

Suitable diols are ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3-or 1,4-butanediol, 1,2-, 1,3-, 1,4- or 1,5-pentanediol, 1,2-, 1,3-,1,4-, 1,5- or 1,6-hexanediol, neopentyl hydroxypivalate, neopentylglycol, diethylene glycol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,2-, 1,3-or 1,4-cyclohexanedimethanol, trimethylpentanediol,ethylbutylpropanediol or the positionally isomeric diethyloctanediols.These diols may also be used per se for the preparation of thepolyurethanes (A) for use in accordance with the invention.

Further examples of suitable diols are diols of the formula I or II:

where R and R¹ are each an identical or different radical and are analkyl radical having 1 to 18 carbon atoms, an aryl radical or acycloaliphatic radical, with the proviso that R and/or R¹ must not bemethyl;

where R², R³, R⁴ and R⁶ are each identical or different radicals and arean alkyl radical having 1 to 6 carbon atoms, a cycloalkyl radical or anaryl radical and R⁴ is an alkanediyl radical having 1 to 6 carbon atoms,an arylene radical or an unsaturated alkenediyl radical having 1 to 6carbon atoms, and n is either 0 or 1.

Suitable diols I of the general formula I are all propanediols in whicheither R or R¹, or R and R¹ is or are not methyl, such as, for example,2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-methyl-1,3-propanediol,2-phenyl-2-methyl-1,3-propanediol, 2-propyl-2-ethyl-1,3-propanediol,2-di-tert-butyl-1,3-propanediol, 2-butyl-2-propyl-1,3-propanediol,1-dihydroxymethylbicyclo[2.2.1]heptane, 2,2-diethyl-1,3-propanediol,2,2-dipropyl-1,3-propanediol or 2-cyclohexyl-2-methyl-1,3-propanediol,et cetera.

Examples of diols II of the general formula II that may be used are2,5-dimethyl-2,5-hexanediol, 2,5-diethyl-2,5-hexanediol,2-ethyl-5-methyl-2,5-hexanediol, 2,4-dimethyl-2,4-pentanediol,2,3-dimethyl-2,3-butanediol, 1,4-(2′-hydroxypropyl)benzene and1,3-(2′hydroxypropyl)benzene.

Of these diols, hexanediol and neopentyl glycol are particularlyadvantageous and are therefore used with particular preference.

The abovementioned diols may also be used per se to prepare thepolyurethane prepolymers (i).

Examples of suitable triols are trimethylolethane, trimethylolpropane orglycerol, especially trimethylolpropane.

The abovementioned triols may also be used per se to prepare thepolyurethane prepolymers (i) (cf. EP 0 339 433 A1).

If desired, minor amounts of monools may also be used. Examples ofsuitable monools are alcohols or phenols such as ethanol, propanol,n-butanol, sec-butanol, tert-butanol, amyl alcohols, hexanols, fattyalcohols, allyl alcohol, or phenol.

The polyester polyols may be prepared in the presence of small Amountsof a suitable solvent as entrainer. Examples of entrainers used arearomatic hydrocarbons, such as especially xylene and (cyclo)aliphatichydrocarbons, e.g., cyclohexane or methylcyclohexane.

Further examples of suitable polyols are polyester diols which areobtained by reacting a lactone with a diol. They are notable for thepresence of terminal hydroxyl groups and repeating polyester fractionsof the formula —(—CO—(CHR⁷)_(m)—CH₂—O—)—. Here, the index m ispreferably from 4 to 6 and the substituent R⁷ is hydrogen or an alkyl,cycloalkyl, or alkoxy radical. No substituent contains more than 12carbon atoms. The total number of carbon atoms in the substituent doesnot exceed 12 per lactone ring. Examples are hydroxycaproic acid,hydroxybutyric acid, hydroxydecanoic acid, and/or hydroxystearic acid.

Preferred for the preparation of the polyester diols is theunsubstituted caprolactone, where m is 4 and all substituents R⁷ arehydrogen. The reaction with lactone is started by low molecular masspolyols such as ethylene glycol, 1,3-propanediol, 1,4-butanedlol, ordlmethylolcyclohexane. It is also possible, however, to react otherreaction componenta, such as ethylenediamine; alkyl-dialkanolamines, orelse urea, with caprolactone. Other suitable diols of relatively highmolecular mass are polylactam diols, which are prepared by reacting, forexample, caprolactam with low molecular mass diols.

Further examples of suitable polyols include polyether polyols,especially those having a number-average molecular weight of from 400 to5000, in particular from 400 to 3000. Examples of highly suitablepolyether diols are polyether diols of the general formulaH—(—O—(CHR⁸)_(o)—)_(p)OH, where the substituent R⁸ is hydrogen or alower, unsubstituted or substitued alkyl radical, the index o is from 2to 6, preferably from 3 to 4, and the index p is from 2 to 100,preferably from 5 to 50. Especially suitable examples are linear orbranched polyether diols such as poly(oxyethylene) glycols,poly(oxypropylene) glycols, and poly(oxybutylene) glycols.

By means of the polyether diols it is possible to introduce nonionichydrophilic functional groups into the main chain(s) of the polyurethaneprepolymers (i).

Hydrophilic polyurethane prepolymers (i) comprise alternatively

-   -   hydrophilic functional groups convertible to cations by        neutralizing agents and/or quaternizing agents, and/or cationic        groups,        or    -   functional groups convertible to anions by neutralizing agents,        and/or anionic groups,        and/or    -   nonionic hydrophilic groups.

Examples of suitable functional groups for use in accordance with theinvention and convertible to cations by neutralizing agents and/orquaternizing agents are primary, secondary or tertiary amino groups,secondary sulfide groups or tertiary phoshine groups, especiallytertiary amino groups or secondary sulfide groups.

Examples of suitable cationic groups for use in accordance with theinvention are primary, secondary, tertiary or quaternary ammoniumgroups, tertiary sulfonium groups or quaternary phosphonium groups,preferably quaternary ammonium groups or tertiary sulfonium groups, butespecially tertiary ammonium groups.

Examples of suitable functional groups for use in accordance with theinvention and convertible to anions by neutralizing agents arecarboxylic acid, sulfonic acid or phosphonic acid groups, especiallycarboxylic acid groups.

Examples of suitable anionic groups for use in accordance with theinvention are carboxylate, sulfonate or phosphonate groups, especiallycarboxylate groups.

Examples of suitable neutralizing agents for functional groupsconvertible to cations are organic and inorganic acids such as formicacid, acetic acid, lactic acid, dimethylolpropionic acid, citric acid,sulfuric acid, hydrochloric acid, and phosphoric acid.

Examples of suitable neutralizing agents for functional groupsconvertible to anions are ammonia or amines, such as trimethylamine,triethylamine, tributylamine, dimethylaniline, diethylaniline,triphenylamine, dimethylethanolamine, diethylethanolamine,methyldiethanolamine, 2-aminomethylpropanol, dimethylisopropylamine,dimethylisopropanolamine or triethanolamine, for example. Neutralizationmay take place in organic phase or in aqueous phase. Preferredneutralizing agents used are dimethylethanolamine and/or triethylamine.

The introduction of hydrophilic functional (potential) cationic groupsinto the polyurethane prepolymers (i) takes place by way of theincorporation of compounds which contain in the molecule at least one,especially two, isocyanate-reactive groups and at least one groupcapable of forming cations; the amount to be used may be calculated fromthe target amine number.

Suitable isocyanate-reactive functional groups are those describedabove. Examples of suitable compounds of this kind are2,2-dimethylolethyl- or -propylamine blocked with a ketone, theresultant ketoxime group being hydrolyzed again prior to the formationof the cationic group, or N,N-dimethyl-, N,N-diethyl- orN-methyl-N-ethyl-2,2-dimethylolethyl- or -propylamine.

The introduction of hydrophilic functional (potentially) anionic groupsinto the polyurethane prepolymers (i) takes place by way of theincorporation of compounds which contain in the molecule at least oneisocyanate-reactive group and at least one group capable of forminganions; the amount to be used may be calculated from the target acidnumber.

Examples of suitable compounds of this kind are those containing twoisocyanate-reactlve groups in the molecule. Here again, suitableisocyanate-reactive groups are those described above. Accordingly it ispossible, for example, to use alkanoic acids having two substituents onthe β carbon atom. The substituent may be a hydroxyl group, an alkylgroup, or, preferably, an alkylol group. These alkanoic acids have atleast one, generally from 1 to 3, carboxyl groups in the molecule. Theyhave 2 to about 25, preferably 3 to 10, carbon atoms. Examples ofsuitable alkanoic acids are dihydroxypropionic acid, dihydroxysuccinicacid, and dihydroxybenzoic acid. A particularly preferred group ofalkanoic acids are the β,β-dimethylolalkanoic acids of the generalformula R—C(CH₂OH)₂OOH, R⁹ being a hydrogen atom or an alkyl grouphaving up to about 20 carbon atoms. Examples of especially suitablealkanoic acids are 2,2-dimethylolacetic acid, 2,2-dimethylolpropionicacid, 2,2-dimenthylolbutyric acid, and 2,2-dimethylolpentanoic acid. Thepreferred dihydroxyaikarinoic acid is 2,2-dimethyiolpropionic acid.Examples of compounds containing amino groups are β,β-diaminovaiericacid, 3,4-diaminobenzoic acid, 2,4-diaminotoluenesulfonic acid, and2,4-dlamlnodiphenyl ether sulfonic acid.

Hydrophilic functional nonionic poly(oxyalkylene) groups may beintroduced as lateral or terminal groups into the polyurethanemolecules. For this purpose it is possible to use not only theabove-described polyether diols but also, for example,alkoxypoly(oxyalkylene) alcohols having the general formulaR¹⁰O—(—CH₂—CHR¹¹—O—)_(r)H, where R¹⁰ is an alkyl radical having 1 to 6carbon atoms, R¹¹ is a hydrogen atom or an alkyl radical having 1 to 6carbon atoms, and the index r is a number between 20 and 75 (cf. patentsEP 0 354 261 A1 or EP 0 424 705 A1).

The hydrophilic functional groups are to be selected so as to rule outthe possibility of any disruptive reactions, such as, for instance, saltformation or crosslinking with the functional groups that may be presentin the other constituents of the polyurethane of the invention, of thegraft copolymers of the invention, of the coating material of theinvention, of the sealing compound of the invention, or of the adhesiveof the invention. The skilled worker will therefore be able to make theselection in a simple manner on the basis of his or her knowledge in theart.

Of these hydrophilic functional (potentially) ionic groups and thehydrophilic functional nonionic groups, the (potentially) anionic groupsare advantageous and are therefore used with particular preference.

To prepare the hydrophilic and the hydrophobic polyurethane prepolymers(i) it is possible to use polyamines and amino alcohols which bringabout an increase in the molecular weight of the polyurethaneprepolymers (i). The essential point in this context is that thepolyamines and amino alcohols are employed in an amount such that thereare still free isocyanate groups remaining in the molecule.

Examples of suitable polyamines have at least two primary and/orsecondary amino groups. Polyamines are essentially alkylene polyamineshaving 1 to 40 carbon atoms, preferably about 2 to 15 carbon atoms. Theymay carry substituents which have no hydrogen atoms that are reactivewith isocyanate groups. Examples are nor vamines having a linear orbranched aliphatic, cycloaliphatic or aromatic structure and at leasttwo primary amino groups.

Diamines include hydrazine, ethylenediamine, propylenediamine,1,4-butylenediamine, piperazine, 1,4-cyclohexyldimethylamine,1,6-hexamethylenediamine, trimethylhexamethylenediamine,menthanediamine, isophoronediamine, 4,4′-diaminodicyclohexylmethane, andaminoethylethanolamine. Preferred diamines are hydrazine, alkyl- orcycloalkyldiamines such as propylenediamine and1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane.

It is also possible to use polyamines containing more than two aminogroups in the molecule. In these cases, however, it should beensured—for example, by using monoamines as well—that no crosslinkedpolyurethane resins are obtained. Polyamines of this kind which may beused are diethylenetriamine, triethylenetetramine, dipropylenediamine,and dibutylenetriamine. An example of a monoamine is ethylhexylamine(cf. patent EP 0 089 497 B1).

Examples of suitable amino alcohols are ethanolamine and diethanolamine.

Furthermore, to prepare the hydrophilic and hydrophobic polyurethaneprepolymers (i) it is possible to use customary and known compounds bymeans of which olefinically unsaturated groups are introduced. As isknown, such compounds contain at least two isocyanate-reactivefunctional groups, especially hydroxyl groups, and at least oneolefinically unsaturated group. Examples of suitable compounds of thiskind are known from DE 197 22 862 C1 or patent applications DE 196 45761 A1, EP 0 522 419 A1 or EP 0 522 420 A1. Where used, they areemployed in minor amounts, so that the profile of properties of thepolyurethanes of the invention is determined by the above-describedolefinically unsaturated groups for use in accordance with theinvention.

The preparation of the polyurethane prepolymers (i) from theconstituents described above has no special features as to method butinstead takes place in accordance with the customary and known methodsof polyurethane chemistry, as known, for example, from the documentsrecited above.

The preparation of the polyurethanes of the invention from theabove-described polyurethane prepolymers (i) and the above-describedcycloaliphatics (ii) and/or cycloolefins (iii), especially thecycloaliphatics (ii), likewise has no special features as to its methodbut instead takes place in bulk or in an inert organic medium,preferably in an inert organic medium, preference being given to the useof polar organic solvents.

It is essential that the reaction takes place until the free isocyanategroup content in the reaction mixture stabilizes or until freeisocyanate groups can no longer be detected. If free isocyanate groupsare present after the reaction, they are preferably reacted with atleast one polyol, polyamine and/or amino alcohol, as described above.This results in an extension of the chain of the polyurethane of theinvention.

The amount of cycloaliphatics (ii) and/or cycloolefins (iii)incorporated by reaction in the polyurethanes of the invention may varyvery widely. Preferably it is from 0.01 to 30, more preferably from 0.1to 25, with particular preference from 0.2 to 20, with very particularpreference from 0.25 to 15, and in particular from 0.3 to 10% by weight,based in each case on the polyurethane of the invention.

The polyurethanes of the invention may be used as such to preparecoating materials, especially paints, and also adhesives and sealingcompounds.

A particular advantage is that the polyurethanes of the invention, owingto their double bond content, may be used to prepare coating materials,especially paints, and also adhesives and sealing compounds, which maybe cured with actinic radiation or by dual cure.

Where the polyurethanes of the invention are hydrophilic, it is ofadvantage in accordance with the invention to use them in the form of adispersion in an aqueous medium The aqueous medium contains essentiallywater. The aqueous medium may include minor amounts of organic solvents,neutralizing agents, crosslinking agents and/or customary coatingsadditives and/or other dissolved solid, liquid or gaseous organic and/orinorganic substances of low and/or high molecular mass. In the contextof the present invention, the term “minor amount” means an amount whichdoes not change the aqueous nature of the aqueous medium. The aqueousmedium, however, may also comprise just water.

For the purpose of dispersion, the hydrophilic polyurethanes of theinvention, containing the above-described (potentially) anionic orcationic hydrophilic groups, are neutralized with at least one of theabove-described neutralizing agents and subsequently are dispersed. Inthe case of the hydrophilic polyurethanes of the invention which containonly the nonionic hydrophilic functional groups, the use of neutralizingagents is unnecessary.

The resultant secondary polyurethane dispersions of the invention arelikewise outstandingly suited to the preparation of aqueous coatingmaterials, adhesives, and sealing compounds. In particular, they aresuitable for preparing the graft copolymers of the invention.

The graft copolymers of the invention are preparable by (co)polymerizingat least one monomer (a) in the presence of at least one polyurethane ofthe invention.

If hydrophilic polyurethanes and predominantly hydrophobic monomers (a)are employed in this preparation, it results in finely divided graftcopolymers of the invention having a hydrophobic core comprising atleast one copolymerized olefinically unsaturated monomer (a) and ahydrophilic shell comprising or consisting of at least one hydrophilicpolyurethane of the invention. This variant of the graft copolymers ofthe invention is prepared by dispersing at least one hydrophilicpolyurethane of the invention in an aqueous medium, and subsequentlyfree-radically (co)polymerizing at least one hydrophobic olefinicallyunsaturated monomer (a) in its presence in emulsion.

If, on the other hand, hydrophobic polyurethanes and predominantlyhydrophilic monomers (a) are employed, the result is finely dividedgraft copolymers of the invention having a hydrophobic core comprisingor consisting of at least one hydrophobic polyurethane of the inventionand a hydrophilic shell comprising at least one hydrophilic,olefinically unsaturated monomer (a) in copolymerized form. This variantis prepared by dispersing at least one hydrophobic polyurethane of theinvention in an aqueous medium. Advantageously, this is done in a strongshear field. Viewed in terms of its method, this process has no specialfeatures, but instead may take place, for example, in accordance withthe dispersion techniques described in European Patent Application EP 0401 565 A1. According to this, at least one hydrophilic olefinicallyunsaturated monomer (a) is (co)polymerized in the presence of thedispersed hydrophobic polyurethanes of the invention.

All conceivable gradations of the hydrophilicity and, respectively, thehydrophobicity of the polyurethanes of the invention on the one hand andof the monomers (a) on the other, between these two extremes, arepossible, so that it is also possible for graft copolymers of theinvention to result which have no, or no pronounced, core-shellstructure.

Furthermore, the graft copolymers of the invention may be prepared usingthe (co)polymerization processes described below.

Examples of hydrophilic and hydrophobic monomers (a) suitable forpreparing the graft copolymers of the invention are the following:

Monomers (a1):

Hydroxyalkyl esters of acrylic acid, methacrylic acid or anotheralpha,beta-ethylenically unsaturated carboxylic acid which are derivedfrom an alkylene glycol which is esterified with the acid, or areobtainable by reacting the acid with alkylene oxide, especiallyhydroxyalkyl esters of acrylic acid, methacrylic acid or ethacrylic acidin which the hydroxyalkyl group contains up to 20 carbon atoms, such as2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl,4-hydroxybutyl acrylate, methacrylate, ethacrylate or crotonate;1,4-bis(hydroxymethyl)cyclohexane,octahydro-4,7-methano-1H-indenedimethanol or methylpropanediolmonoacrylate, monomethacrylate, monoethacrylate or monocrotonate; orreaction products of cyclic esters, such as ε-caprolactone, for example,and these hydroxyalkyl esters; or olefinically unsaturated alcohols suchas allyl alcohol or polyols such as trimethylolpropane monoallyl ordiallyl ether or pentaerythritol monoallyl, diallyl or triallyl ether.These monomers (a1) of higher functionality are generally used only inminor amounts. In the context of the present invention, minor amounts ofhigher-functional monomers here are amounts which do not result in thecrosslinking or gelling of the polyacrylate resins. Thus, for example,the proportion of trimethylolpropane monoallyl ether may be from 2 to10% by weight, based on the overall weight of the monomers (a1) to (a6)used to prepare the polyacrylate resin.

Monomers (a2):

(Meth)acrylic alkyl or cycloalkyl esters having up to 20 carbon atoms inthe alkyl radical, especially methyl, ethyl, propyl, n-butyl, sec-butyl,tert-butyl, hexyl, ethylhexyl, stearyl and lauryl acrylate ormethacrylate; cycloaliphatic (meth)acrylic esters, especiallycyclohexyl, isobornyl, dicyclopentadienyl,octahydro-4,7-methano-1H-indenedimethanol or tert-butylcyclohexyl(meth)acrylate; (meth)acrylic oxaalkyl esters or oxacycloalkyl esterssuch as ethyltriglycol (meth)acrylate and methoxyoligoglycol(meth)acrylate having a molecular weight Mn of preferably 550; or otherethoxylated and/or propoxylated hydroxyl-free (meth)acrylic acidderivatives. These may include, in minor amounts, higher-functional(meth)acrylic alkyl or cycloalkyl esters such as ethylene glycol,propylene glycol, diethylene glycol, dipropylene glycol, butyleneglycol, 1,5-pentanediol, 1,6-hexanediol,octahydro-4,7-methano-1H-indenedimethanol or cyclohexane-1,2-, -1,3- or-1,4-diol di(meth)acrylate; trimethylolpropane di- or tri(meth)acrylate;or pentaerythritol di-, tri- or tetra(meth)acrylate. In the context ofthe present invention, minor amounts of higher-functional monomers (a2)here are amounts which do not cause crosslinking or gelling of thepolyacrylate resins.

Monomers (a3):

Ethylenically unsaturated monomers which carry at least one acid group,preferably a carboxyl group, per molecule, or a mixture of suchmonomers. As monomers (a3) it is particularly preferred to use acrylicacid and/or methacrylic acid. It is also possible, however, to use otherethylenically unsaturated carboxylic acids having up to 6 carbon atomsin the molecule. Examples of such acids are ethacrylic acid, crotonicacid, maleic acid, fumaric acid, and itaconic acid. It is also possibleto use ethylenically unsaturated sulfonic or phosphonic acids, and/ortheir partial esters, as component (a3). Further suitable monomers (a3)include mono(meth)acryloyloxyethyl maleate, succinate, and phthalate.

Monomers (a4):

Vinyl esters of alpha-branched monocarboxylic acids having 5 to 18carbon atoms in the molecule. The branched monocarboxylic acids may beobtained by reacting formic acid or carbon monoxide and water witholefins in the presence of a liquid, strongly acidic catalyst; theolefins may be cracking products from paraffinic hydrocarbons, such asmineral oil fractions, and may contain both branched and straight-chainacyclic and/or cycloaliphatic olefins. In the reaction of such olefinswith formic acid and/or with carbon monoxide and water, a mixture ofcarboxylic acids is formed in which the carboxyl groups are locatedpredominantly on a quaternary carbon atom. Other olefinic startingmaterials are, for example, propylene trimer, propylene tetramer, anddiisobutylene. Alternatively, the vinyl esters may be prepared in aconventional manner from the acids, for example, by reacting the acidwith acetylene. Particular preference—owing to their readyavailability—is given to the use of vinyl esters of saturated aliphaticmonocarboxylic acids having 9 to 11 carbon atoms and being branched onthe alpha carbon atom.

Monomers (a5):

Reaction product of acrylic acid and/or methacrylic acid with theglycidyl ester of an alpha-branched monocarboxylic acid having 5 to 18carbon atoms per molecule. The reaction of the acrylic or methacrylicacid with the glycidyl ester of a carboxylic acid having a tertiaryalpha carbon atom may take place before, during or after thepolymerization reaction. As component (a5) it is preferred to use thereaction product of acrylic and/or methacrylic acid with the glycidylester of Versatic® acid. This glycidyl ester is obtainable commerciallyunder the name Cardura® E10. For further details, reference is made toRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart,N.Y., 1998, pages 605 and 606.

Monomers (a6):

Ethylenically unsaturated monomers essentially free from acid groups,such as

-   -   olefins, such as ethylene, propylene, 1-butene, 1-pentene,        1-hexene, cyclohexene, cyclopentene, norbornene, butadiene,        isoprene, cyclopentadiene and/or dicyclopentadiene;    -   (meth)acrylamides such as (meth)acrylamide, N-methyl-,        N,N-dimethyl-, N-ethyl-, N,N-diethyl-, N-propyl-, N,N-dipropyl,        N-butyl-, N,N-dibutyl-, N-cyclohexyl- and/or        N,N-cyclohexyl-methyl(meth)acrylamide;    -   monomers containing epoxide groups, such as the glycidyl ester        of acrylic acid, methacrylic acid, ethacrylic acid, crotonic        acid, maleic acid, fumaric acid and/or itaconic acid;    -   vinylaromatic hydrocarbons, such as styrene,        alpha-alkylstyrenes, especially alpha-methylstyrene, and/or        vinyltoluene;    -   diarylethylenes, especially those of the general formula III:        R¹²R¹³C=CR¹⁴R¹⁵  (III)        where the radicals R¹², R¹³, R¹⁴ and R¹⁵ each independently of        one another are hydrogen atoms or substituted or unsubstituted        alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl,        alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl radicals,        with the proviso that at least two of the variables R¹², R¹³,        R¹⁴ and R¹⁵ are substituted or unsubstituted aryl, arylalkyl or        arylcycloalkyl radicals, especially substituted or unsubstituted        aryl radicals. Examples of suitable alkyl radicals are methyl,        ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, amyl,        hexyl or 2-ethylhexyl. Examples of suitable cycloalkyl radicals        are cyclobutyl, cyclopentyl or cyclohexyl. Examples of suitable        alkylcycloalkyl radicals are methylenecyclohexane,        ethylenecyclohexane, or 1,3-propanediylcyclohexane. Examples of        suitable cyloalkylalkyl radicals are 2-, 3- or 4-methyl-,        -ethyl-, -propyl- or -butylcyclohex-1-yl. Examples of suitable        aryl radicals are phenyl, naphthyl or biphenylyl, preferably        phenyl and naphthyl, and especially phenyl. Examples of suitable        alkylaryl radicals are benzyl or ethylene- or        1,3propanediyl-benzene. Examples of suitable cycloalkylaryl        radicals are 2-, 3- or 4-phenylcyclohex-1-yl. Examples of        suitable arylalkyl radicals are 2-, 3- or 4-methyl-, -ethyl-,        -propyl- or -butylphen-l-yl. Examples of suitable arylcycloalkyl        radicals are 2-, 3- or 4-cyclohexylphen-1-yl. The aryl radicals        R¹², R¹³, R¹⁴ and/or R¹⁵ are preferably phenyl or naphthyl        radicals, especially phenyl radicals. The substituents that may        be present in the radicals R¹², R¹³, R¹⁴ and/or R¹⁵ are electron        withdrawing or electron donating atoms or organic radicals,        especially halogen atoms, nitrile, nitro, partially or fully        halogenated alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl,        aryl, alkylaryl, cycloalkylaryl, arylalkyl and arylcycloalkyl        radicals; aryloxy, alkyloxy and cycloalkyloxy radicals;        arylthio, alkylthio and cycloalkylthio radicals, and/or primary,        secondary and/or tertiary amino groups. Diphenylethylene,        dinaphthaleneethylene, cis- or trans-stilbene,        vinylidene-bis(4-N,N-dimethylaminobenzene),        vinylidenebis(4-aminobenzene) or vinylidenebis(4-nitrobenzene),        especially diphenylethylene (DPE), are particularly advantageous        and so are used with preference. Preferably, these monomers (a6)        are used not as the sole monomers but rather always together        with other monomers (a), in which case they regulate the        copolymerization advantageously such that free-radical        copolymerization in batch mode is also possible;    -   nitrites such as acrylonitrile and/or methacrylonitrile;    -   vinyl compounds such as vinyl chloride, vinyl fluoride,        vinylidene dichloride, vinylidene difluoride;        N-vinylpyrrolidone; vinyl ethers such as ethyl vinyl ether,        n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl        ether, isobutyl vinyl ether and/or vinyl cyclohexyl ether; vinyl        esters such as vinyl acetate, vinyl propionate, vinyl butyrate,        vinyl pivalate, vinyl esters of Versatic® acids, which are        marketed under the brand name VeoVa® by the company Deutsche        Shell Chemie (for further details, reference is made to Römpp        Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart,        N.Y., 1998, page 598 and also pages 605 and 606), and/or the        vinyl ester of 2-methyl-2-ethylheptanoic acid; and/or    -   polysiloxane macromonomers having a number-average molecular        weight Mn of from 1000 to 40,000, preferably from 2000 to        20,000, with particular preference from 2500 to 10,000, and in        particular from 3000 to 7000, and having on average from 0.5 to        2.5, preferably from 0.5 to 1.5, ethylenically unsaturated        double bonds per molecule, as are described in DE 38 07 571 A1        on pages 5 to 7, in DE 37 06 095 A1 in columns 3 to 7, in EP 0        358 153 B1 on pages 3 to 6, in U.S. Pat. No. 4,754,014 A in        columns 5 to 9, in DE 44 21 823 A1, or in international Patent        Application WO 92/22615 on page 12 line 18 to page 18 line 10,        or acryloxysilane-containing vinyl monomers, preparable by        reacting hydroxy-functional silanes with epichlorohydrin and        then reacting the reaction product with methacrylic acid and/or        hydroxyalkyl esters of (meth)acrylic acid.

From these suitable monomers (a) described above by way of example, theskilled worker is easily able to select, on the basis of their knownphysicochemical properties and reactivities, the hydrophilic orhydrophobic monomers (a) that are particularly suitable for the intendeduse in question. If desired, he or she may for this purpose conduct afew preliminary rangefinding experiments. In particular, he or she willbe careful to ensure that monomers (a) contain no functional groups,especially (potentially) ionic functional groups, which enter intounwanted interactions with the (potentially) ionic functional groups inthe hydrophilic polyurethanes of the invention.

In accordance with the invention, particular advantages result if themonomers (a) are selected such that the profile of properties of thegrafted (co)polymers is determined essentially by the above-describedhydrophilic or hydrophobic (meth)acrylate monomers (a), the othermonomers (a) advantageously providing broad variation of this profile ofproperties.

In accordance with the invention, very particular advantages result fromusing mixtures of the monomers (a1), (a2) and (a6) and also, if desired,(a3).

Viewed in terms of method, the preparation of the graft copolymers ofthe invention has no special features but instead takes place inaccordance with the customary and known methods of free-radical(co)polymerization in bulk, solution or emulsion in the presence of atleast one polymerization initiator.

Where the (co)polymerization takes place in bulk or solution, the graftcopolymer of the invention may be used or processed further in thisform. In particular, it is dispersed in an aqueous medium, so giving asecondary dispersion of the invention.

The (co)polymerization is preferably conducted in emulsion, such as isdescribed, for example, in patent DE 197 22 862 C1 or in patentapplications DE 196 45 761 A1, EP-A-522 419 A1 or EP 0 522 420 A1, or inminiemulsion or microemulsion. Regarding miniemulsion and microemulsion,reference is made, for further details, to the patent applications andthe literature references DE 196 28 142 A1, DE 196 28 143 A1 or EP 0 401565 A1, emulsion polymerization and emulsion polymers, editors P. A.Lovell and Mohamed S. El-Aasser, John Wiley and Sons, Chichester, N.Y.,Weinheim, 1997, pages 700 et seq.; Mohamed S. El-Aasser, Advances inEmulsion Polymerization and Latex Technology, 30th Annual Short Course,Volume 3, Jun. 7-11, 1999, Emulsion Polymers Institute, LehighUniversity, Bethlehem, Pa., U.S.A. In the case of (co)polymerization inemulsion, miniemulsion or microemulsion, the graft copolymers of theinvention are obtained in the form of primary dispersions of theinvention.

Suitable reactors for the (co)polymerization processes are the customaryand known stirred vessels, cascades of stirred vessels, tube reactors,loop reactors or Taylor reactors, as described, for example, in patentsDE-B-1 071 241 A1, EP 0 498 583 A1 or DE 198 28 742 A1 or in the articleby K. Kataoka in Chemical Engineering Science, Volume 50, No. 9, 1995,pages 1409 to 1416.

The (co)polymerization is advantageously conducted at temperatures aboveroom temperature and below the lowest decomposition temperature of themonomers used in each case, the temperature range chosen beingpreferably from 30 to 180° C., with very particular preference from 70to 150° C., and in particular from 80 to 110° C.

Where especially volatile monomers (a) and/or emulsions are used, the(co)polymerization may also be conducted under superatmosphericpressure, preferably under from 1.5 to 3000 bar, with particularpreference from 5 to 1500 bar, and in particular from 10 to 1000 bar.

Examples of suitable polymerization initiators are initiators which formfree radicals, such as dialkyl peroxides, such as di-tert-butyl peroxideor dicumyl peroxide; hydroperoxides, such as cumene hydroperoxide ortert-butyl hydroperoxide; peresters, such as tert-butyl perbenzoate,tert-butyl perpivalate, tert-butyl per-3,5,5-trimethylhexanoate, ortert-butyl per-2-ethylhexanoate; potassium, sodium or ammoniumperoxodisulfate; azo dinitriles such as azobisisobutyronitrile;C—C-cleaving initiators such as benzpinacol silyl ether; or acombination of a nonoxidizing initiator with hydrogen peroxide.Preference is given to the use of water-insoluble initiators. Theinitiators are used preferably in an amount of from 0.1 to 25% byweight, with particular preference from 2 to 10% by weight, based on theoverall weight of the monomers (a).

In the graft copolymers of the invention the proportion of core to shellor of polyurethane of the invention to grafted-on monomers (a) may varyextremely widely, which is a particular advantage of the graftcopolymers of the invention. This ratio is preferably from 1:100 to100:1, more preferably from 1:50 to 50:1, with particular preferencefrom 30:1 to 1:30, with very particular preference from 20:1 to 1:20,and in particular from 10:1 to 1:10. Very particular advantages resultif this ratio is approximately from 3.5:1 to 1:3.5, in particular from1.5:1 to 1:1.5.

The graft copolymers of the invention may be isolated from the primarydispersions in which they are produced and may be passed on for a verywide variety of end uses, especially in solventborne, water- andsolvent-free pulverulent solid or water- and solvent-free liquid coatingmaterials, adhesives, and sealing compounds. In accordance with theinvention, however, it is of advantage to use the primary dispersions assuch se to prepare aqueous coating materials, adhesives, and sealingcompounds.

In addition to the polyurethanes of the invention and the graftcopolymers of the invention, the aqueous adhesives of the invention maycomprise further suitable customary and known constituents in effectiveamounts. Examples of suitable constituents are the crosslinking agentsand additives described below, provided they are suitable for preparingadhesives.

In addition to the polyurethanes of the invention and the graftcopolymers of the invention, the aqueous sealing compounds of theinvention may likewise comprise further suitable customary and knownconstituents in effective amounts. Examples of suitable constituents arelikewise the crosslinking agents and additives described below, providedthey are suitable for preparing sealing compounds.

The primary dispersions of the graft copolymers of the invention areespecially suitable for preparing the aqueous coating materials of theinvention, especially the aqueous coating materials of the invention.Examples of aqueous coating materials of the invention are surfacers,solid-color topcoats, aqueous basecoats, and clearcoats. The primarydispersions of the invention develop very particular advantages whenused to prepare the aqueous basecoats of the invention.

In the aqueous basecoats of the invention, the polyurethanes and/or thegraft copolymers of the invention, but especially the graft copolymersof the invention, are present advantageously in an amount of from 1.0 to50, preferably from 2.0 to 40, with particular preference from 3.0 to35, with very particular preference from 4.0 to 30, and in particularfrom 5.0 to 25% by weight, based in each case on the overall weight ofthe respective aqueous basecoat of the invention.

The further essential constituent of the aqueous basecoat of theinvention is at least one color and/or effect pigment. The pigments maycomprise organic or inorganic compounds. On the basis of this largenumber of appropriate pigments, therefore, the aqueous basecoat of theinvention ensures a universal scope for use and makes it possible torealize a large number of color shades and optical effects.

Effect pigments which may be used include metal flake pigments such ascommercial aluminum bronzes, aluminum bronzes chromated in accordancewith DE-A-36 36 183, commercial stainless steel bronzes, and nonmetalliceffect pigments, such as pearlescent pigments and interference pigments,for example. For further details, reference is made to Römpp LexikonLacke und Druckfarben, Georg Thieme Verlag, 1998, page 176, “Effectpigments” and pages 380 and 381 “Metal oxide-mica pigments” to “Metalpigments”.

Examples of suitable inorganic color pigments are titanium dioxide, ironoxides, sicotrans yellow, and carbon black. Examples of suitable organiccolor pigments are thioindigo pigments, indanthrene blue, Cromophthalred, Irgazine orange and Heliogen green. For further details, referenceis made to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,1998, pages 180 and 181, “Iron blue pigments” to “Black iron oxide”,pages 451 to 453 “Pigments” to “Pigment volume concentration”, page 563“Thioindigo pigments”, and page 567 “Titanium dioxide pigments”.

The proportion of the pigments in the aqueous basecoat of the inventionmay vary extremely widely and is guided in particular by the hidingpower of the pigments, by the desired shade, and by the desired opticaleffect. Preferably, the pigments are present in the aqueous basecoat ofthe invention in an amount of from 0.5 to 50, more preferably from 0.5to 45, with particular preference from 0.5 to 40, with very particularpreference from 0.5 to 35, and in particular from 0.5 to 30% by weight,based in each case on the overall weight of the aqueous basecoat of theinvention. In this context, the pigment/binder ratio, i.e., the ratio ofthe pigments to the polyurethanes of the invention and/or to the graftcopolymers of the invention, and also other binders that may be present,may vary extremely widely. Preferably, this ratio is from 6.0:1.0 to1.0:50, more preferably from 5:1.0 to 1.0:50, with particular preferencefrom 4.5:1.0 to 1.0:40, with very particular preference from 4:1.0 to1.0:30, and in particular from 3.5:1.0 to 1.0:25.

These pigments may also be incorporated into the aqueous basecoats ofthe invention by way of pigment pastes, in which case suitable grindingresins include, inter alia, the polyurethanes of the invention and/orthe graft copolymers of the invention.

These pigments are omitted when the coating material of the invention isused as a clearcoat.

The coating material of the invention, especially the aqueous basecoatof the invention, may comprise at least one crosslinking agent.

Examples of suitable crosslinking agents are amino resins, as describedfor example in Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,1998, page 29, “Amino resins”, in the text book “Lackadditive” [Coatingsadditives] by Johan Bieleman, Wiley-VCH, Weinheim, N.Y., 1998, pages 242et seq., in the book “Paints, Coatings and Solvents”, second, completelyrevised edition, edited by D. Stoye and W. Freitag, Wiley-VCH, Weinheim,N.Y., 1998, pages 80 ff., in patents U.S. Pat. No. 4 710 542 A1 orEP-B-0 245 700 A1, and in the article by B. Singh and coworkers,“Carbamylmethylated melamines, Novel Crosslinkers for the CoatingsIndustry” in Advanced Organic Coatings Science and Techology Series,1991, Volume 13, pages 193 to 207; carboxyl-containing compounds orresins, as described for example in patent DE 196 52 813 A1; compoundsor resins containing epoxide groups, as described for example in patentsEP 0 299 420 A1, DE 22 14 650 B1, DE 27 49 576 B1, U.S. Pat. No.4,091,048 A1 or U.S. Pat. No. 3,781,379 A1; blocked and nonblockedpolyisocyanates, as described for example in patents U.S. Pat. No.4,444,954 A1, DE 196 17 086 A1, DE 196 31 269 A1, EP 0 004 571 A1 or EP0 582 051 A1; and/or tris(alkoxycarbonylamino)triazines, as described inpatents U.S. Pat. No. 4,939,213 A1, U.S. Pat. No. 5,084,541 A1, U.S.Pat. No. 5,288,865 A1 or EP 0 604 922 A1.

The epoxides and the nonblocked polyisocyanates, especially thepolyisocyanates, are employed in two-component or multicomponentsystems.

Where the aqueous basecoats of the invention are one-component systems,it is preferred to use amino resins as the predominant or solecrosslinking agents. The other abovementioned crosslinking agents may beused as additional crosslinking agents for further advantageousvariation of the profile of properties of the aqueous basecoats of theinvention and of the basecoats of the invention and multicoat colorand/or effect coating systems of the invention produced therefrom, inwhich case their proportion among the crosslinking agents is <50% byweight.

Preferably, the crosslinking agents are employed in the aqueousbasecoats of the invention in an amount of from 0.1 to 30, morepreferably from 0.3 to 20, with particular preference from 0.5 to 10,and in particular from 1.0 to 8.0% by weight, based in each case on theoverall weight of the respective aqueous basecoat of the invention.

In addition to the above-described constituents, the coating material ofthe invention, especially the aqueous basecoat, may comprise customaryand known binders and/or additives in effective amounts.

Examples of customary and known binders are oligomeric and polymeric,thermally curable, linear and/or branched and/or block, comb and/orrandom poly(meth)acrylates or acrylate copolymers, especially thosedescribed in patent DE 197 36 535 A1, polyesters, especially thosedescribed in patents DE 40 09 858 A1 or DE 44 37 535 A1, alkyds,acrylated polyesters, polylactones, polycarbonates, polyethers, epoxyresinamine adducts, (meth)acrylate diols, partially hydrolyzed polyvinylesters, polyurethanes and acrylated polyurethanes, as described inpatents EP 0 521 928 A1, EP 0 522 420 A1, EP 0 522 419 A1, EP 0 730 613A1 or DE 44 37 535 A1, or polyureas.

If the coating material of the invention is to be curable not onlythermally but also with actinic radiation, especially UV radiationand/or electron beams (dual cure), it comprises at least one constituentwhich is activatable with actinic radiation.

Suitable activatable constituents are in principle all oligomeric andpolymeric compounds that are curable with actinic radiation, especiallyUV radiation and/or electron beams, and which are commonly used in thefield of UV-curable or electron-beam-curable coating materials.

It is advantageous to use radiation-curable binders as activatableconstituents. Examples of suitable radiation-curable binders are(meth)acrylic-functional (meth)acrylic copolymers, polyether acrylates,polyester acrylates, unsaturated polyesters, epoxy acrylates, urethaneacrylates, amino acrylates, melamine acrylates, silicone acrylates,isocyanato acrylates, and the corresponding methacrylates. It ispreferred to use binders which are free from aromatic structural units.Preference is therefore given to the use of urethane (meth)acrylatesand/or polyester (meth)acrylates, aliphatic urethane acrylates beingparticularly preferred.

Examples of suitable additives are

-   -   organic and inorganic fillers such as chalk, calcium sulfate,        barium sulfate, silicates such as talc or kaolin, silicas,        oxides such as aluminum hydroxide or magnesium hydroxide, or        organic fillers such as textile fibers, cellulose fibers,        polyethylene fibers or wood flour; for further details reference        is made to Römpp Lexikon Lacke und Druckfarben, Georg Thieme        Verlag, 1998, pages 250 ff., “Fillers”;    -   thermally curable reactive diluents such as positionally        isomeric diethyloctanediols or hydroxyl-containing hyperbranched        compounds or dendrimers, as described in patent applications DE        198 09 643 A1, DE 198 40 605 A1 or DE 198 05 421 A1;    -   reactive diluents curable with actinic radiation, as described        in Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,        Stuttgart, N.Y., 1998, on page 491 under the entry “Reactive        diluents”;    -   photoinitiators and coinitiators, as described in Römpp Lexikon        Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, 1998,        pages 444 to 446;    -   low-boiling and/or high-boiling organic solvents (“long        solvents”);    -   UV absorbers;    -   light stabilizers such as HALS compounds, benzotriazoles or        oxalanilides;    -   free-radical scavengers;    -   thermally labile free-radical initiators such as organic        peroxides, organic azo compounds or C—C-cleaving initiators such        as dialkyl peroxides, peroxocarboxylic acids,        peroxodicarbonates, peroxide esters, hydroperoxides, ketone        peroxides, azo dinitriles or benzpinacol silyl ether;    -   crosslinking catalysts such as dibutyltin dilaurate, lithium        decanoate or zinc octoate, or amine-blocked organic sulfonic        acids;    -   devolatilizers such as diazadicycloundecane;    -   slip additives;    -   polymerization inhibitors;    -   defoamers;    -   emulsifiers, especially nonionic emulsifiers such as alkoxylated        alkanols, polyols, phenols and alkylphenols or anionic        emulsifiers such as alkali metal salts or ammonium salts of        alkanecarboxylic acids, alkanesulfonic acids and sulfo acids of        alkoxylated alkanols, polyols, phenols and alkylphenols;    -   wetting agents such as siloxanes, fluorine compounds, carboxylic        monoesters, phosphates, polyacrylic acids and their copolymers,        or polyurethanes;    -   adhesion promoters such as tricyclodecanedimethanol;    -   leveling agents;    -   film-forming auxiliaries such as cellulose derivatives;    -   transparent fillers based on titanium dioxide, silica, alumina        or zirconium oxide; for further details reference is made to        Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,        Stuttgart, 1998, pages 250 to 252;    -   rheology control additives, such as those known from patents WO        94/22968, EP 0 276 501 A1, EP 0 249 201 A1 or WO 97/12945;        crosslinked polymeric microparticles, as disclosed for example        in EP 0 008 127 A1; inorganic phyllosilicates, preferably        smectites, especially montmorillonites and hectorites, such as        aluminum-magnesium silicates, sodium-magnesium and        sodium-magnesium-fluorine-lithium phyllosilicates of the        montmorillonite type or inorganic phyllosilicates such as        aluminum-magnesium silicates, sodium-magnesium and        sodium-magnesium-fluorine-lithium phyllosilicates of the        montmorillonite type (for further details reference is made to        the book by Johan Bieleman, “Lackadditive”, Wiley-VCH, Weinheim,        N.Y., 1998, pages 17 to 30); silicas such as Aerosils; or        synthetic polymers containing ionic and/or associative groups        such as polyvinyl alcohol, poly(meth)acrylamide,        poly(meth)acrylic acid, polyvinylpyrrolidone, styrene-maleic        anhydride or ethylene-maleic anhydride copolymers and their        derivatives or hydrophobically modified polyacrylates; or        associative thickeners based on polyurethane, as described in        Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag,        Stuttgart, N.Y., 1998, “Thickeners”, pages 599 to 600, and in        the textbook “Lackadditive” by Johan Bieleman, Wiley-VCH,        Weinheim, N.Y., 1998, panes 51 to 59 and 65; and/or    -   flame retardants.

Further examples of suitable coatings additives are described in thetextbook “Lackadditive” by Johan Bieleman, Wiley-VCH, Weinheim, N.Y.,1998.

The aqueous basecoats of the invention preferably have spray viscosityand a solids content of from 5.0 to 60, more preferably from 10 to 60,with particular preference from 13 to 60, and in particular from 13 to55% by weight, based in each case on the overall weight of therespective aqueous basecoat of the invention.

The preparation of the aqueous basecoat of the invention has no specialfeatures but instead takes place in a customary and known manner bymixing of the above-described constituents in appropriate mixingequipment such as stirred vessels, dissolvers, stirred mills orextruders in accordance with the techniques suitable for preparing therespective aqueous basecoats.

The aqueous basecoat of the invention is used to produce the coatings ofthe invention, especially multicoat coating systems, on primed orunprimed substrates.

Suitable substrates are all surfaces for coating which are not damagedby curing of the coatings present thereon using heat, or heat andactinic radiation. Suitable substrates comprise, for example, metals,plastics wood, ceramic, stone, textile, fiber assemblies, leather,glass, glass fibers, glass wool and rock wool, mineral-bound andresin-bound building materials, such as plasterboards and cement boardsor roof tiles, and composites of these materials. Accordingly, theaqueous basecoat of the invention is suitable for applications outsidethat of vehicle finishing as well. In this context it is particularlysuitable for the coating of furniture and for industrial coating,including coil coating, container coating, and the impregnation orcoating of electrical components. In the context of industrial coatingsit is suitable for coating virtually all parts for domestic orindustrial use, such as radiators, domestic appliances, small metalparts such as screws and nuts, wheel caps, wheel rims, packaging, orelectrical components such as motor windings or transformer windings.

The comments made above also apply, mutatis mutandis, to the surfacers,solid-color topcoats, and clearcoats of the invention, and to theadhesives and sealing compounds of the invention.

In the case of electrically conductive substrates it is possible to useprimers, which are prepared in a customary and known manner fromelectrodeposition coating materials. Both anodic and cathodicelectrodeposition coating materials are suitable for this purpose, butespecially cathodics.

With the multicoat coating system of the invention it is also possibleto coat primed or unprimed plastics such as, for example, ABS, AMMA,ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA, PE, HDPE, LDPE, LLDPE,UHMWPE, PET, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM,PUR-RIM, SMC, BMC, PP-EPDM and UP (abbreviations to DIN 7728P1) and alsopolymer blends thereof or the fiber-reinforced composite materialsproduced using these plastics.

In the case of unfunctionalized and/or apolar substrate surfaces, thesemay be subjected prior to coating in a known manner to a pretreatment,such as with a plasma or by flaming, or may be provided with an aqueousprimer.

The multicoat coating systems of the invention may be produced in avariety of ways in accordance with the invention.

A first preferred variant of the process of the invention comprises thefollowing process steps:

-   -   (I) preparing a basecoat film by applying the aqueous basecoat        of the invention to the substrate,    -   (II) drying the basecoat film,    -   (III) preparing a clearcoat film by applying a clearcoat        material to the basecoat film, and    -   (IV) jointly curing the basecoat film and the clearcoat film, to        give the basecoat and the clearcoat (wet-on-wet technique).

This variant offers particular advantages especially in the context ofthe coating of plastics, and is therefore employed with particularpreference in that utility.

A second preferred variant of the process of the invention comprises thefollowing steps:

-   -   (I) preparing a surfacer film by applying a surfacer to the        substrate,    -   (II) curing the surfacer film, to give the surfacer coat,    -   (III) preparing a basecoat film by applying the aqueous basecoat        of the invention to the surfacer coat,    -   (IV) drying the basecoat film,    -   (V) preparing a clearcoat film by applying a clearcoat material        to the basecoat film, and    -   (VI) jointly curing the basecoat film and the clearcoat film, to        give the basecoat and the clearcoat (wet-on-wet technique).

A third preferred variant of the process of the invention comprises thefollowing steps:

-   -   (I) preparing a surfacer film by applying a surfacer to the        substrate,    -   (II) drying the surfacer film,    -   (III) preparing a basecoat film by applying the aqueous basecoat        of the invention to the surfacer film,    -   (IV) drying the basecoat film,    -   (V) preparing a clearcoat film by applying a clearcoat material        to the basecoat film, and    -   (VI) jointly curing the surfacer film, the basecoat film and the        clearcoat film, to give the surfacer, the basecoat and the        clearcoat (extended wet-on-wet technique).

A fourth preferred variant of the process of the invention comprises thefollowing steps:

-   -   (I) depositing an electrodeposition coating film on the        substrate,    -   (II) drying the electrodeposition coating film,    -   (II) preparing a first basecoat film by applying a first        basecoat material to the electrodeposition coating film,    -   (III) jointly curing the electrodeposition coating film and the        first basecoat film, to give the electrodeposition coating and        the first basecoat (wet-on-wet technique),    -   (IV) preparing a second basecoat film by applying a second        basecoat material to the first basecoat,    -   (V) drying the second basecoat film,    -   (VI) preparing a clearcoat film by applying a clearcoat material        to the basecoat film, and    -   (VII) jointly curing the second basecoat film and clearcoat        film, to give the second basecoat and the clearcoat (wet-on-wet        technique).

The three last-mentioned variants offer particular advantages especiallyin the context of the coating of automobile bodies and are thereforeemployed with very particular preference in that utility.

It is a further particular advantage of the aqueous basecoat of theinvention and of the processes of the invention that the aqueousbasecoat may be combined not only with the surfacer of the invention butalso with all customary and known surfacers.

Yet another special advantage of the aqueous basecoat of the inventionand of the process of the invention proves to be that the aqueuosbasecoat may be combined not only, outstandingly, with the clearcoatmaterial of the invention but also with all customary and knownclearcoat materials.

Clearcoat materials which are known per se are one-component ormulticomponent clearcoats, powder clearcoats, powder slurry clearcoats,UV-curable clearcoats, or sealers, as known from the patentapplications, patents and publications DE 42 04 518 A1, EP 0 594 068 A1,EP 0 594 071 A1, EP 0 594 142 A1, EP 0 604 992 A1, EP 0 596 460 A1, WO94/10211, WO 94/10212, WO 94/10213, WO 94/22969 or WO 92/22615, U.S.Pat. No. 5,474,811 A1, U.S. Pat. No. 5,356,669 A1 or U.S. Pat. No.5,605,965 A1, DE 42 22 194 A1, in the product information from BASFLacke+Farben AG entitled “Pulverlacke” [Powder coatings], 1990, in theBASF Coatings AG company brochure “Pulverlacke, Pulverlacke furindustrielle Anwendungen” [Powder coating materials, powder coatings forindustrial applications], January 2000,

U.S. Pat. No. DE 195 40 977 A1, DE 195 18 392 A1, 4,268,542 A1, DE 19617 086 A1, DE-A-196 13 547, DE 196 52 813 A1, DE-A-198 14 471 A1, EP 0928 800 A1, EP 0 636 669 A1, EP 0 410 242 A1, EP 0 783 534 A1, EP 0 650978 A1, EP 0 650 979 A1, EP 0 650 985 A1, EP 0 540 884 A1, EP 0 568 967A1, EP 0 054 505 A1, EP 0 002 866 A1, DE 197 09 467 A1, DE 42 03 278 A1,DE 33 16 593 A1, DE 38 36 370 A1, DE 24 36 186 A1, DE 20 03 579 B1, WO97/46549, WO 99/14254, U.S. Pat. No. 5,824,373 A1, U.S. Pat. No. U.S.Pat. No. U.S. Pat. No. 4,675,234 A1, 4,634,602 A1, 4,424,252 A1, U.S.Pat. No. U.S. Pat. No. U.S. Pat. No. 4,208,313 A1, 4,163,810 A1,4,129,488 A1, U.S. Pat. No. U.S. Pat. No. EP 0 844 286 A1, 4,064,161 A1,3,974,303 A1, DE 43 03 570 A1, DE 34 07 087 A1, DE 40 11 045 A1, DE 4025 215 A1, DE 38 28 098 A1, DE 40 20 316 A1 or DE 41 22 743 A1.

Powder slurry clearcoats offer particular advantages for the multicoatcolor and/or effect coating system of the invention and are thereforeused with particular preference in accordance with the invention.

Furthermore, the clearcoats may additionally be coated further with atleast one other clearcoat, for example, an organically modified ceramiclayer, thereby making it possible to improve significantly the scratchresistance of the multicoat coating system of the invention.

The aqueous basecoat of the invention may be applied by all customaryapplication methods, such as spraying, knifecoating, brushing,flowcoating, dipping, impregnating, trickling, or rolling, for example.The substrate to be coated may itself be at rest, with the applicationequipment or unit being moved. Alternatively, the substrate to becoated, especially a coil, may be moved, with the application unit beingat rest relative to the substrate or being moved appropriately.

Preference is given to the use of spray application methods, such ascompressed-air spraying, airless spraying, high-speed rotation,electrostatic spray application (ESTA), alone or in conjunction with hotspray applications such as hot-air spraying, for example. Applicationmay be conducted at temperatures of max. 70 to 80° C., so that suitableapplication viscosities are achieved without the short-term thermalstress being accompanied by any change in or damage to the aqueousbasecoat or its overspray, which may be intended for reprocessing. Forinstance, hot spraying may be configured such that the aqueous basecoatis heated in the spray nozzle for only a very short time, or is heatedjust a short way upstream of the spray nozzle.

The spray booth used for the application may be operated, for example,with an optionally temperature-controllable circulation, which isoperated with an appropriate absorption medium for the overspray, anexample being the aqueous basecoat itself.

In general, the surfacer coating film, basecoat film and clearcoat filmare applied in a wet film thickness such that they cure to give coatshaving the coat thicknesses which are necessary and advantageous fortheir functions. In the case of the surfacer coat, this coat thicknessis from 10 to 150, preferably from 10 to 120, with particular preferencefrom 10 to 100, and in particular from 10 to 90 μm; in the case of thebasecoat it is from 5 to 50, preferably from 5 to 40, with particularpreference from 5 to 30, and in particular from 10 to 25 μm; and in thecase of the clearcoats it is from 10 to 100, preferably from 15 to 80,with particular preference from 20 to 70, and in particular from 25 to60 μm. It is also possible, however, to employ the multicoat systemknown from European Patent Application EP 0 817 614 A1, comprising anelectrodeposition coat, a first basecoat, a second basecoat, and aclearcoat, in which the overall coat thickness of the first and secondbasecoats is from 15 to 40 μm and the coat thickness of the firstbasecoat is from 20 to 50% of said overall coat thickness.

The surfacer coating film, basecoat film and clearcoat film are clearedthermally, or thermally and with actinic radiation (dual cure).

Full curing may take place after a certain rest time. Its duration maybe from 30 s to 2 h, preferably from 1 min to 1 h, and in particularfrom 1 min to 45 min. The rest time serves, for example, for the coatingfilms to flow and undergo devolatilization, or for the evaporation ofvolatile constituents such as solvents. The rest time may be assistedand/or shortened by the application at elevated temperatures of up to90° C. and/or by a reduced atmospheric humidity <10 g water/kg air,especially <5 g/kg air, provided this does not entail any damage orchange to the coating films, such as premature complete crosslinking,for instance.

The thermal curing has no special features in terms of its method butinstead takes place in accordance with the customary and known methods,such as heating in a convection oven or irradiation with IR lamps. Thisthermal curing may also take place in stages.

Advantageously, thermal curing takes place at a temperature of from 50to 100° C., with particular preference from 60 to 100° C., and inparticular from 80 to 100° C., for a time of from 1 min up to 2 h, withparticular preference from 2 min up to 1 h, and in particular from 3 minto 45 min. This process is employed in particular in the case oftwo-component or multicomponent systems.

If one-component systems and substrates of high heat-resistance areused, thermal crosslinking may also be conducted at temperatures above1000° C. In this case it is generally advisable not to exceedtemperatures of 180° C., preferably 160° C., and in particular 155° C.

Curing with actinic radiation is preferably conducted with UV radiationand/or electron beams. It is preferred to employ a dose of from 1000 to3000, preferably from 1100 to 2900, with particular preference from 1200to 2800, with very particular preference from 1300 to 2700, and inparticular from 1400 to 2600 mJ/cm². If desired, this curing may besupplemented by actinic radiation from other radiation sources. In thecase of electron beams, it is preferred to operate under an inert gasatmosphere. This may be ensured, for example, by supplying carbondioxide and/or nitrogen directly to the surface of the coating films.When curing with UV radiation, as well, it is also possible to operateunder inert gas in order to prevent the formation of ozone.

For curing with actinic radiation, the customary and known radiationsources and optical auxiliary measures are employed. Examples ofsuitable radiation sources are flashlights from the company VISIT,high-pressure or low-pressure mercury vapor lamps, with or without leaddoping in order to open up a radiation window of up to 405 nm, orelectron beam sources. The arrangement of these sources is known inprinciple and may be adapted to the circumstances of the workpiece andthe process parameters. In the case of workpieces of complex shape, asenvisaged for automobile bodies, the regions not accessible to directradiation (shadow regions) such as cavities, folds and other structuralundercuts may be (partially) cured using point emitters, small surfacearea emitters or circular emitters, in combination with an automaticmovement means for the irradiation of cavities or edges.

The apparatus and conditions for these curing methods are described, forexample, in R. Holmes, U.V. and E.B. Curing Formulations for PrintingInks, Coatings and Paints, SITA Technology, Academic Press, London,United Kingdom 1984.

Curing may be carried out in stages, i.e., by means of multiple exposureto light or with actinic radiation. It may also be carried outalternatingly; ie., curing is conducted in alternation with UV radiationand electron beams.

If thermal curing and curing with actinic radiation are employedtogether, these methods may be used simultaneously or in alternation. Ifthe two curing methods are used in alternation, it is possible, forexample, to begin with thermal curing and to end with actinic radiationcuring. In other cases it may prove advantageous to begin with curingwith actinic radiation and to end with it. Particular advantages resultif the aqueous basecoat film is cured in two separate process steps,first with actinic radiation and then thermally.

The application and curing techniques described above are also employedwith the other coating films (surfacer films, solid-color topcoat films,clearcoat films) and also with the adhesives and sealing compounds ofthe invention.

The multicoat coating systems of the invention exhibit an outstandingprofile of properties which is very well balanced in terms of mechanics,optics, corrosion resistance, and adhesion. Thus the multicoat coatingsystems of the invention possess the high optical quality and intercoatadhesion required by the market and do not give rise to any problemssuch as deficient condensation resistance, cracking (mudcracking) orleveling defects, or surface structures in the clearcoats.

In particular, the multicoat coating systems of the invention exhibit anoutstanding metallic effect, an excellent D.O.I. (distinctness of thereflected image), and an outstanding surface smoothness. They areweathering-stable, resistant to chemicals and bird droppings, arescratch resistant, and exhibit very good reflow behavior.

Last but not least, however, it proves to be a very special advantagethat through the use of the aqueous basecoats of the invention in theproduction of the multicoat coatings of the invention no cracking orpopping marks result even when the aqueous basecoat films are overcoatedwith powder slurry clearcoats and subsequently baked together with them.By this means it is possible to combine the particular advantages ofaqueous basecoats with the particular advantages of powder slurryclearcoats. Moreover, these very multicoat coating systems of theinvention prove to be particularly firmly adhering, even when used asrefinishes.

The adhesives and sealing compounds of the invention are outstandinglysuitable for the production of adhesive films and seals, which retainparticularly high bond strength and particularly high sealing capacityeven under extreme and/or rapidly changing climatic conditions.

Accordingly, the primed or unprimed substrates of the invention coatedwith at least one coating of the invention, bonded with at least oneadhesive film of the invention, and/or sealed with at least one seal ofthe invention, combine a particularly advantageous profile ofperformance properties with a particularly long service life, so makingthem particularly valuable economically.

EXAMPLES AND COMPARATIVE EXPERIMENTS Example 1

The Preparation of an Inventive Polyurethane

In a reaction vessel equipped with stirrer, internal thermometer, refluxcondenser and electrical heating, 701 parts by weight of a linearpolyester polyol (prepared from dimerized fatty acid (Pripol® 1013),isophthalic acid and 1,6-hexanediol) having a hydroxyl number of 80 anda number-average molecular weight of 1400 daltons, 41.5 parts by weightof vinylcyclohexanediol and 99.7 parts by weight of dimethylolpropionicacid were dissolved in 404 parts by weight of methyl ethyl ketone and123 parts by weight of N-methylpyrrolidone. 388.8 parts by weight ofisophorone diisocyanate were added to the resulting solution at 45° C.After the exothermic reaction had subsided, the reaction mixture wasslowly heated to 80° C. with stirring. It was stirred further at thistemperature until the isocyanate content remained constant at 1.1% byweight. The reaction mixture was then cooled to 60° C. and 36.7 parts byweight of diethanolamine were added. The resulting reaction mixture wasstirred at 60° C. until free isocyanate groups were no longerdetectable. The resulting dissolved polyurethane was admixed with 137parts by weight of methoxypropanol and 55 parts by weight oftriethylamine. 30 minutes after adding the amine, 1500 parts by weightof deionized water were added with stirring over the course of 30minutes. The methyl ethyl ketone was removed from the resultingdispersion by distillation under reduced pressure at 60° C. Thereafter,any losses of solvent and of water were compensated. The resultantdispersion of the polyurethane of the invention was adjusted to a solidscontent of 35.1% by weight (one hour at 130° C.) and a pH of 7.3.

Example 2

The Preparation of an Inventive Primary Dispersion of a Graft Copolymer

1487.2 parts by weight of the polyurethane dispersion from Example 1were diluted with 864.4 parts by weight of deionized water and heated to85° C. At this temperature, a mixture of 150.2 parts by weight ofstyrene, 150.2 parts by weight of methyl methacrylate, 112.4 parts byweight of n-butyl acrylate and 112.4 parts by weight of hydroxyethylmethacrylate were added to the dispersion at a uniform rate over thecourse of 3.5 hours with stirring. At the same time as commencing theaddition of the monomer mixture, a solution of 7.9 parts by weight oftert-butyl peroxyethylhexanoate in 115.5 parts by weight ofmethoxypropanol was added over the course of four hours. The weightratio of polyurethane to monomers was 1:1. The resulting reactionmixture was stirred at 85° C. until all of the monomers had reacted. Theresulting primary dispersion of the graft copolymer had a very goodstorage stability. Its solid content was 35.7% by weight (one hour at130° C.) and its pH was 7.2.

Comparative Experiment C1

The Preparation of a Known Polyurethane Containing Lateral Vinyl Groups

A hydroxyl-containing polyester was prepared in accordance with patentEP 0 608 021 A1, page 6 lines 22 to 37 (intermediate A). For thispurpose, a mixture of 236 parts by weight of 1,6-hexanediol, 208 partsby weight of neopentyl glycol, 616 parts by weight of hexahydrophthalicanhydride and 6 parts by weight of benzyltriphenylphosphonium chloridewas charged to an appropriate reaction vessel and heated to 120° C.under nitrogen and with stirring. After one hour at this temperature,the reaction mixture was heated to 140° C. Subsequently, 1000 parts byweight of the glycidyl ester of 1,1-dimethyl-1-heptanecarboxylic acid(Cardura® E-10 from Shell) were metered in over two hours. After fourhours, the reaction mixture had an acid number of 8.5 mg KOH/g. Afurther 80 parts by weight of Cardura® E-10 were added. After anothertwo hours, the acid number of the reaction mixture was less than 1 mgKOH/g.

In accordance with the instructions given on page 7 lines 1 to 27(Example I) of patent EP 0 608 021 A1, 261.6 parts by weight of theabove-described polyester, 55 parts by weight of N-methylpyrrolidone and0.1 part by weight of dibutyltin diacetate were taken as initial charge.72.1 parts by weight of isophorone diisocyanate were metered into thismixture over the course of one hour at 90° C. After two hours at 90° C.,the reaction mixture was heated to 100° C. At this temperature, 16.3parts by weight of 1-(1-isocyanato-1-methylethyl)-3-(1-methyle (TMI®from Cytec) were metered in over 15 minutes. The resulting reactionmixture was held at 100° C. for one hour.

Thereafter, the reaction mixture was heated to 130° C. and at thistemperature a mixture of 38.2 parts by weight of styrene, 9.2 parts byweight of methyl methacrylate, 33.1 parts by weight of acrylic acid, 66parts by weight of Cardura® E-10, 2.7 parts by weight of dicumylperoxide, 0.8 part by weight of 3-mercaptopropionic acid and 51.9 partsby weight of 2-butoxyethanol was added over the course of one hour undernitrogen and with stirring. The resulting reaction mixture was held atthis temperature for three hours. Subsequently, at 115° C., 18.1 partsby weight of dimethylethanolamine were metered in. After the mixture hadcooled to 90° C., 782 parts by weight of deionized water were metered indropwise with stirring over three hours, giving a secondary dispersionhaving a solids content of 35.8% by weight.

Example 3 and Comparative Experiments C2 and C3

The Preparation of an Inventive Aqueous Basecoat (Example 3) andNoninventive Aqueous Basecoats (Comparative Experiments C2 and C3)

For the inventive example 3, 9.5 parts by weight of deionized water werecharged to a mixing vessel. With stirring, 10.5 parts by weight of anaqueous acrylate dispersion [component (i) in accordance with patent DE197 36 535 A1; Acronal® 290 D from BASF Aktiengesellschaft], 13.5 partsby weight of the inventive primary dispersion of Example 2, 10.4 partsby weight of the thickener 1 (paste of a synthetic sodium magnesiumphyllosilicate from Laporte, 3% in water), 8.0 parts by weight ofdeionized water, 0.28 part by weight of a 15% strength aqueous ammoniasolution and 18.0 parts by weight of a thickener 2 (3% strength aqueoussolution of a polyacrylic acid thickener from Allied Colloids) wereadded.

Subsequently, with stirring, 4.2 parts by weight of a pigment pastehaving a carbon black content of 10% by weight and containing 60% byweight of the acrylated polyurethane dispersion in accordance withExample D of patent DE 44 37 535 A1, 10.2 parts by weight of a fillerpaste having an Aerosil content of 10% by weight and containing 50% byweight of the acrylated polyurethane dispersion in accordance withExample D of patent DE 44 37 535 A1, 2.0 parts by weight of butyl glycoland 3.5 parts by weight of a methanol- and butanol-etherified melamineresin from CYTEC were added.

In a separate mixing vessel, a mixture of 0.4 part by weight of acommercial aluminum bronze (AluStapa Hydrolux® from Eckart, Al content65% by weight) and 0.6 part by weight of butyl glycol was stirredtogether. This mixture was subsequently added in portions and withvigorous stirring to the other mixture.

In a further separate mixer, 1.3 parts by weight of a pearlescentpigment (Iriodin® 9103 Sterling Silber WR from Merck) and 2.3 parts byweight of butyl glycol were mixed. This mixture was subsequently addedin portions, again with vigorous stirring, to the mixture describedabove.

Table 1 gives an overview of the composition of the inventive aqueousbasecoat of Example 3.

For comparative experiment C2, Example 3 was repeated but replacing theinventive primary dispersion of Example 2 by the aqueous polyurethaneresin dispersion of Example 1 of patent DE 43 39 870 A1 [component(ii)].

For comparative experiment C3, Example 3 was repeated but replacing theinventive primary dispersion of Example 2 by the known secondarydispersion of comparative experiment C1. The material composition of thenoninventive aqueous basecoats C3 and C2 is likewise given in Table 1.

TABLE 1 The composition of the inventive aqueous basecoat (Example 3)and of the noninventive aqueous basecoats (comparative experiments C2and C3) Comparative experiments: Example: Constituents C2 C3 3 Deionizedwater 9.5 9.5 9.5 Component (i) 10.5 10.5 10.5 Component (ii) 13.5 — —Secondary — 13.5 — dispersion C1 Primary dispersion — — 13.5 (Ex. 2)Thickener 1 10.4 10.4 10.4 Deionized water 8.0 8.0 8.0 Ammonia solution0.28 0.28 0.28 Thickener 2 18.0 18.0 18.0 Pigment paste 4.2 4.2 4.2Filler paste 10.2 10.2 10.2 Butyl glycol 2.0 2.0 2.0 Melamine resin 3.53.5 3.5 Aluminum paste 0.4 0.4 0.4 Butyl glycol 0.6 0.6 0.6 Iriodin 91031.3 1.3 1.3 Butyl glycol 2.3 2.3 2.3

The viscosity of the aqueous basecoats of Table 1 was adjusted usingdeionized water to from 90 to 95 mPas at a shear rate of 1000/s.

Example 4 and Comparative Experiments C4 and C5

The Preparation of an Inventive Multicoat System (Example 4) and ofNoninventive Multicoat Systems (Comparative Experiments C4 and C5)

The inventive multicoat system of Example 4 was prepared using theinventive aqueous basecoat of Example 3 (cf. Table 1).

The noninventive multicoat system of comparative experiment C4 wasprepared using the noninventive aqueous basecoat of comparativeexperiment C2 (cf. Table 1).

The noninventive multicoat system of comparative experiment C5 wasprepared using the noninventive aqueous basecoat of comparativeexperiment C3 (cf. Table 1).

A. The Preparation of the Test Panels:

For example 4 and the Comparative experiments C4 and C5, test panelswere first of all prepared. This was done by coating steel panels(bodywork panels), which had been coated with a customary and knowncathodically deposited and baked electrodeposition coating, with acommercial thin-film surfacer (Ecoprime® 60 from BASF Coatings AG;anthracite-colored), after which the resulting surfacer film was flashedoff at 20° C. and a relative atmospheric humidity of 65% for fiveminutes and dried at 80° C. in a convection oven for five minutes.Subsequently, the filler film had a dry film thickness of 15 μm.

Following the cooling of the test panels to 20° C., the aqueousbasecoats of table 1 were applied, flashed off at 20° C. and a relativeatmospheric humidity of 65% for five minutes and dried at 80° C. in aconvection oven for five minutes, so that the dried basecoat films had adry film thickness of approximately 15 μm.

After the test panels had again been cooled to 20° C., the basecoatfilms were overcoated with a powder slurry clearcoat material inaccordance with International Patent Application WO 96/32452. Theresulting powder slurry clearcoat films were flashed off at 20° C. and arelative atmospheric humidity of 65% for 3 minutes, and dried at 55° C.in a convection oven for five minutes. The dry film thickness of theresulting clearcoat films was from 50 to 60 μm.

Following the application of all three films, they were baked jointly at155° C. for 30 minutes, to give the inventive multicoat system ofExample 4 and the noninventive multicoat systems of the comparativeexperiments C4 and C5.

B. The Production of Refinish Coats:

To simulate the refinishing of the entire body on the line (linerefinish), the test panels from Example 4 and from the comparativeexperiments C4 and C5 were sanded with a 1200 grit sandpaper and, inaccordance with the instructions described above, were coated again withthe same multicoat system in each case (double coating).

C. The Determination of the Popping Limit and Cracking Limit(Mudcracking):

In accordance with the instructions given in section A. above, multicoatsystems were produced in which the basecoats were applied in a wedgefrom 3 to 40 μm. The clearcoats had a coat thickness of from 55 to 57μm. The cracking limit and popping limit indicate the coat thicknessabove which surface defects (in this case popping marks and mudcracking)appear in the clearcoat. The cracking limit and the popping limit are ameasure of the compatibility of the aqueous basecoat material with theclearcoat material, or of the basecoat with the clearcoat; the higherthe cracking limit or the popping limit, the better the compatibility.The corresponding results are given in Table 2.

D. The Testing of the Clearcoat Adhesion:

The clearcoat adhesion was tested on unstressed test panels [cf. sectionA. above (original finish) and section B. above (refinish)] after threedays of storage at room temperature. For this purpose, using a knife ora pointed mandrel, the multicoat systems were scored down to the steelsurface. The score marks were then subjected to a jet of water underhigh pressure for one minute (high-pressure cleaner from Karcher), thewater pressure being 230 bar, the water temperature 20° C., and thedistance of the rotating spray nozzle from the test panels 6 cm.Assessment was made visually: if the multicoat system showed no damage,it was assessed as being “satisfactory” (sat.). If delaminationoccurred, this was assessed as being “unsatisfactory” (unsat.). Theresults are likewise given in Table 2.

E. The Testing of the Intercoat Adhesion After Ball Shot Testing:

Ball shot testing was carried out in accordance with the DaimlerChryslerspecification, which is general knowledge among those in the art. Thecorresponding results are likewise given in Table 2.

F. The Testing of the Intercoat Adhesion After Constant Humidity ClimateExposure to DIN 50017:

The test panels produced in accordance with the instructions indicatedin section A. were subjected to the constant humidity climate of DIN50017. Subsequently, after 0 and 2 hours of regeneration, the intercoatadhesion was determined using the cross-cut test in accordance with DINEN ISO 2409. The results are likewise given in Table 2.

TABLE 2 The results of the tests of sections C. to F. Comparativeexperiments: Example: Tests C4 C5 4 Section C.: Cracking limit (μm): 2812 36 Popping limit (μm) 23 13 29 Section D.: Water jet test: unsat.¹⁾unsat.¹⁾ sat. Section E.: Ball shot testing: Original finish  6/0 12/0 6/0 Refinish 16/0 35/0 14/0 Section F.: Cross-cut test: After 0 hours'GT0 GT3 GT0 regeneration After 2 hours' GT0 GT1-2 GT0 regeneration¹⁾Extensive clearcoat delamination

The results of Table 2 demonstrate that the inventive aqueous basecoatof Example 3 and the inventive multicoat system of Example 4 wereclearly superior to the noninventive aqueous basecoats of comparativeexperiments C2 and C3 and to the noninventive multicoat systems ofcomparative experiments C4 and C5 in terms of the compatibility ofaqueous basecoat and powder slurry clearcoat and in terms of theintercoat adhesion. Furthermore, they underscore the incompatibility ofthe noninventive aqueous basecoat C3 with the powder slurry clearcoatand the very poor individual chip resistance of the noninventivemulticoat system C5 produced using it.

1. A hydrophilic or hydrophobic polyurethane having at least oneolefinically unsaturated group selected from the group consisting ofpendant olefinically unsaturated groups, terminal olefinicallyunsaturated groups, and mixtures thereof, wherein the pendantolefinically unsaturated groups are selected from the group consistingof pendant olefinically unsaturated groups which are attached to acycloaliphatic group which represents a link in the polymer main chainend pendant olefinically unsaturated groups which are present as adouble bond in a cycloolefinic group which constitutes a link in thepolymer main chain, and the terminal olefinically unsaturated groups areselected from the group consisting of terminal olefinically unsaturatedgroups which are attached to a cycloaliphatic group which forms anendgroup of the polymer main chain and terminal olefinically unsaturatedgroups which are present as a double bond in a cycloolefinic structurewhich forms an endgroup of the polymer main chain.
 2. The polyurethaneas claimed in claim 1, wherein the pendant or terminal olefinicallyunsaturated groups attached to the cycloaliphatic groups are selectedfrom the group consisting of (meth)acrytate, ethacrylate, crotonate,cinnamate, vinyl ether, vinyl ester, vinyl, dicyclopentadienyl,norbormenyl, isoprenyl, isopropenyl, allyl, butenyl groups,dlcyclopentadienyl ether, norbormenyl ether, isoprenyl ether,isopropenyl ether, allyl ether, butenyl ether groups; dicyclopentadienylester, norbormenyl ester, isoprenyl ester, isopropenyl ester, allylester, butenyl ester groups, and mixtures thereof.
 3. The polyurethaneof claim 2, wherein the olefinically unsaturated groups are vinylgroups.
 4. The polyurethane of claim 1, wherein the cycloaliphaticgroups are selected from the group consisting of cycloaliphatics having4 to 12 carbon atoms in the molecule and the cycloolefinic groups areselected from the group consisting of cycloolefins having 4 to 12 carbonatoms in the molecule.
 5. The polyurethane of claim 4, wherein thecycloaliphatic groups are selected from the group consisting ofcyclobutene, cyclopentane, cyclohexane, cycloheptane, cycloctane,norbornane, bicyclo[2.2.2]octante, decalin, hydroindane, dicylcopentene,tricyclodecane, and adamantine, and the cycloolefinic groups areselected from the group consisting of cyclopentene, cyclohexene,cycloheptene, cyclooctene, norbornene, bicyclo[2.2.2]octane, anddicylclopentene.
 6. The polyurethane of claim 1, made by reacting (i) atleast one polyurethane prepolymer having at least one free isocyanategroup in the molecule with a member selected from the group consistingof (ii) at least one cycloaliphatic having at least one olefinicallyunsaturated group and having at least two isocyanate-reactive groups inthe molecule, (iii) at least one cycloolefin having at least twoisocyanate-reactive groups in the molecule, and mixtures thereof.
 7. Thepolyurethane of claim 6, wherein the cycloaliphatics (II) and/orcycloolefins (III) contain two Isocyanate-reactive groups in themolecule.
 8. The polyurethane of claim 6, wherein theisocyanate-reactive groups are selected from the group consisting ofhydroxyl, thiol, primary amino groups, secondary amino groups, andmixtures thereof.
 9. The polyurethane of claim 8, wherein theisocyanate-reactive groups are hydroxyl groups.
 10. The polyurethane ofclaim 6, characterized in that the cycloaliphatics (ii) comprise anolefinically unsaturated group.
 11. The polyurethane of claim 10,wherein the olefinically unsaturated groups are selected from the groupconsisting of (meth)acrylate, ethacrylate, crotonate, cinnamate, vinylether, vinyl ester, vinyl, dicyclopentadienyl, norbormenyl, isoprenyl,isopropenyl, allyl, butenyl groups, dicyclopentadienyl ether,norbormenyl ether, isoprenyl ether, isopropenyl ether, allyl ether orbutenyl ether groups, dicyclopentadienyl ester, norbormenyl ester,isoprenyl ester, isopropenyl ester, allyl ester, butenyl ester groups,and mixtures thereof.
 12. The polyurethane of claim 11, wherein theolefinically unsaturated groups are vinyl groups.
 13. The polyurethaneof claim 10, wherein the cycloaliphatics (ii) are selected from, thegroup consisting of positionally isomeric vinyl-substituted polyhydroxyderivatives of cyclobutane, cyclopentane, cyclohexane, cycloheptane,cycloctane, norbornane, bicyclo[2.2.2]octane, decalin, hydroindane,dicylcopentene, tricyclodecane, and adamantane and the cycloolefins(iii) are selected from the group consisting of positionally isomericpolyhydroxy derivatives of cyclopentene, cyclohexene, cycloheptene,cyclooctene, norbornene, bicyclo[2.2.2]octane, and dicylclopentene. 14.The polyurethane of claim 13, wherein the cycloaliphatics (ii) or thecycloolefins (iii) are positionally isomeric dihydroxy derivatives. 15.The polyurethane of claim 14 wherein the positionally isomeric dihydroxyderivative is vinylcyclohexanediol.
 16. The polyurethane of claim 6,wherein the polyurethane prepolymer is prepared from at least onediisocyanate and at least one compound having two isocyanate-reactivegroups.
 17. A graft copolymer prepared by (co)polymerizing at least onemonomer (a) in the presence of at least one polyurethane of claim
 1. 18.A method of making a sealing compound, adhesive, or coating material,comprising using at least one polyurethane of claim
 1. 19. A sealingcompound, adhesive, or coating material comprising at least one memberselected from the group consisting of a polyurethane of claim 1, a graftcopolymer of claim 17, or mixtures thereof.
 20. A hydrophilic orhydrophobic polyurethane having at least one olefinically unsaturatedgroup selected from the group consisting of pendant olefinicallyunsaturated groups, terminal olefinically unsaturated groups, andmixtures thereof, wherein the pendant olefinically unsaturated groupsare selected from the group consisting of pendant olefinicallyunsaturated groups which are attached to a cycloaliphatic group whichrepresents a link in the polymer main chain and pendant olefinicallyunsaturated groups which are present as a double bond in a cycloolefinicgroup which constitutes a link in the polymer main chain, and theterminal olefinically unsaturated groups are selected from the groupconsisting of terminal olefinically unsaturated groups which areattached to a cycloaliphatic group which forms an endgroup of thepolymer main chain and terminal olefinically unsaturated groups whichare present as a double bond in a cycloolefinic structure which forms anendgroup of the polymer main chain, the polyurethane made by reacting(iv) at least one polyurethane prepolymer having at least one freeisocyanate group in the molecule with a member selected from the groupconsisting of (v) at least one cycloaliphatic having at least oneolefinically unsaturated group and having at least twoisocyanate-reactive groups in the molecule, (vi) at least onecycloolefin having at least two isocyanate-reactive groups in themolecule, and mixtures thereof.